the cape mole-rat ( georychus capensis ) is a species of mole-rat endemic to south africa .

it is the only living species in the genus georychus .

cape mole - rat

bennett explained that the mole rat is neither a mole nor a rat , but rather that “they look like a rat , but act like a mole” .
seismic signal transmission between burrows of the cape mole - rat , georychus capensis .
nutrition and burrowing energetics of the cape mole - rat georychus capensis . - pubmed - ncbi
the cape mole rat ( georychus capensis ) is a rodent in the bathyergidae family of blesmols and was also known as the cape sand - mole .
) are subterranean rodent moles endemic to sub - saharan africa . the cape mole - rat (
seismic signal transmission between burrows of the cape mole - rat , georychus capensis . - pubmed - ncbi
bathyergus suillus ( cape dune mole - rat ) , rondevlei nature reserve , cape town , south africa . [ photo trevor hardaker © ]
ectoparasite burdens of the common mole - rat ( cryptomys hottentotus hottentotus ) from the cape provinces of south africa .
cape mole rats are found in the southwestern and southern parts of the cape of good hope province in south africa .
the biomass of the entire colony is generally around 2000g , which is about the weight of an individual mole rat of one of the larger solitary species , such as the cape dune mole - rat .
with the headline : scientists amazed by the mole rat ' s bizarre behavior .
a . time measurements for spatial novelty in the y - maze for the cape mole - rat . during the test phase , laboratory maintained cape mole - rats showed a strong preference to the novel arm compared to their wild counterparts . b . activity measures show that during the test phase , wild cape mole - rats enter all three arms of the maze more often than laboratory cape mole - rat .
ectoparasite burdens of the common mole - rat ( cryptomys hottentotus hottentotus ) from the cape provinces of south africa . - pubmed - ncbi
the damaraland mole rat ( cryptomys damarensis ) is the only other eusocial mammal currently known .
watch out , mole rat ! feat . parry gripp ( music video ) | party animals playlist
what made you want to look up cape mole rat ? please tell us where you read or heard it ( including the quote , if possible ) .
one major unanswered question is how the queen mole rat suppresses the ability of other females to reproduce .
the damaraland mole rat is one of the social species . the solitary ones are found in areas where food is more available , such as in parts of the western cape . mole rat colonies are found in places like the kalahari where food distribution is patchy and spread out .
it is normal for cape mole rats to have 3 pairs of mammae but 4 are not unusual .
) . investigation of other mole - rat species will be informative in understanding the evolutionary gains and losses of these neural substrates within the family . a recent study on another social species , ansell ' s mole - rat
the rather boldly marked cape mole - rat or blesmol ( georychus capensis ) in life . photo by nigel c . bennett , cc by - sa 3 . 0 .
goldblatt , p . and manning , j . c . 2000 . cape plants : a conspectus of the cape flora of south africa . strelitzia 9 . national botanical institute , cape town .
ron stoppable , lead male character in the tv series kim possible , has a pet naked mole rat named rufus .
because of their extraordinary longevity , an international effort was put into place to sequence the genome of the naked mole rat .
absence of histamine - induced itch in the african naked mole - rat and
rescue
by substance p .
jarvis jum ( 1981 ) eusociality in a mammal : cooperative breeding in naked mole - rat colonies . science 212 : 571–573
kimchi t , terkel j ( 2001 ) spatial learning and memory in the blind mole - rat in comparison with the laboratory rat and levant vole . anim behav 61 : 171 - 180 . doi :
number of corpora lutea and atretic follicles ( mean ± se ) per section of ovarian tissue for cape dune mole - rat individuals captured from january 2003 to january 2004 in cape town , south africa . solid bars denote corpora lutea and hatched bars denote atretic follicles .
mole launching .
blowing up moles in my yard . wack - a - mole . rodenator .
cape mole rats feed on tubors and roots and may affect plant communities . their burrowing behavior probably helps to aerate the soil .
for a while the general assumption seemed to be that the eusociality of the naked mole - rat had evolved from the also eusocial but less ‘extreme’ biology of the cryptomys and fukomys common mole - rats… or , at least , evolved from common - mole - rat - like mole - rats . these eusocial mole - rats ( the eusocial common mole - rats and the naked mole - rat ) inhabit more arid places than most other mole - rats , and they’re the most specialised when it comes to reliance on geophytes and roots , so the idea of some sort of trend toward arid - land specialisation , ever - smaller size , geophyte / root specialisation and increasing eusociality looked like a possibility .
the naked mole rat is native to the drier parts of the tropical grasslands of east africa , predominantly southern ethiopia , kenya , and somalia .
pepper jw , braude sh , lacey ea , sherman pw ( 1991 ) vocalization of the naked mole - rat . in : sherman pw , jarvis jum , alexander rd ( eds ) the biology of the naked mole - rat . princeton university press , princeton new jersey , pp 243–274
zoology department , university of cape town , 7700 , rondebosch , south africa .
fluctuation in a ) progesterone concentration ( nmol / ml ) and b ) 17β - estradiol concentration ( pg / liter ) in female cape dune mole - rats captured at the cape town international airport , cape town , south africa , from january 2003 to january 2004 ( mean ± se ) .
percentage of female cape dune mole - rats captured that were pregnant or lactating captured at cape town , south africa , from january 2003 to january 2004 . dashed lines denote pregnant females and solid lines denote lactating females .
the naked mole rat , heterocephalus glaber , is neither mole nor rat . a species unique in the two known classes of mole rats that exist , it is believed to be the only hairless rodent in the world . in size and shape , its body resembles a small sausage , while its protruding front teeth make it look like a miniature walrus .
the social structure and reproductive biology of the common mole rat , cryptomys h . hottentotus and remarks on the trends in reproduction and sociality in the family
younge , c . a . 2000 . cape action plan for the environment . a biodiversity strategy and action plan for the cape floral kingdom . wwf - sa , stellenbosch .
a naked mole - rat queen - either cute and nice to look at , or the grotesque stuff of nightmares . image by chomez , in public domain .
lacey ea , alexander rd , braude sh , sherman pw , jarvis jum ( 1991 ) an ethogram for the naked mole - rat : non vocal behaviours . in : sherman pw , jarvis jum , alexander rd ( eds ) the biology of the naked mole - rat . princeton university press , princeton new jersey , pp 209–242
sherman pw , jarvis jum , alexander rd ( eds ) ( 1991 ) the biology of the naked mole - rat . princeton university press , princeton , new jersey
jarvis jum ( 1991 ) reproduction of naked mole - rats . in : sherman pw , jarvis jum , alexander rd ( eds ) the biology of the naked mole - rat . princeton university press , princeton new jersey , pp 384–425
honeycutt rl , nelson k , schlitter da , sherman pw ( 1991 ) genetic variation within and among populations of the naked mole - rat : evidence from nuclear and mitochondrial genomes . in : sherman pw , jarvis jum , alexander rd ( eds ) the biology of the naked mole - rat . princeton university press , princeton new jersey , pp 195–208
the diet of cape mole rats consists almost exclusively of below ground plant parts , although they have been know to ingest insects , especially ants . the main burrow of
) where , compared to surface dwelling rodents , they performed comparably . moreover , when tested over time , the blind mole - rat outperformed the other rodents in terms of memory retention [
both wild and captive mole - rats showed a significant reduction in time to reach the escape hole over four days , indicating the acquisition of reference memory . the ability of subterranean rodents to build a reference memory has also been demonstrated in the blind mole –rat (
a . time related exploration measurements in the tunnel maze for the cape mole - rat . the latency to enter the first tunnel was longer for laboratory animals , however the difference was not significant . the total time spent in the tunnels and the mean time per visit revealed no differences . b . activity measures shows that wild cape mole - rats were more active than their laboratory counterparts , both in terms of tunnel entries and the number of tunnels visited ( max 3 ) .
is used for food storage of tubers , roots , and bulbs . cape mole rats have been know to bite off the buds of bulbs and tubers to stop them from growing .
the naked mole rat is also of interest because it is extraordinarily long - lived for a rodent of its size ( up to 28 years ) and holds the record for the longest living rodent .
fluctuation in volume ( mm 3 ) of the testes and ovaries of the cape dune mole - rats captured from january 2003 to january 2004 in cape town , south africa . solid bars denote males and hatched bars denote females . sample sizes for each group are indicated above the respective bars .
jennifer u . m . jarvis , a zoologist at the university of cape town in south africa and the third member of the team , is credited with pioneering the study of the naked mole rat with her work in kenya several years ago . the research has been partly financed by the national geographic society .
in the fynbos of the south - western cape , south africa . j zool ( lond ) 209 : 125–147
micromammals , owls and vegetation change in the eastern cape midlands , south africa , during the last . . .
experimental animals were captured in during two field trips using hickman live traps [ 15 ] . female cape mole - rats were collected near darling , western cape , south africa ( 33 ° 22’ s , 15 ° 25’ e ) . animals were transported to the university of pretoria where experiments were conducted .
bennett nc ( 1988 ) the trend toward sociality in three species of southern african mole - rats ( bathyergidae ) : causes and consequences . ph . d . thesis , university of cape town
determining social status associated with a host of factors is also difficult . very little agressive behavior has been observed within mole rat colonies , with the exception of shoving behavior by the queen . however other cues have been used to derive theoretical social heiarchies from the availible data . one such cue is the passing behavior of mole rats in tunnels . almost always one rat will pass over the another rat , rather than passing side by side . it has been suggested that the dominant individual in a pair will be the one that passes on top .
du toit l , bennett nc , nickless a , whiting mj ( 2012 ) influence of spatial environment on maze learning in an african mole - rat . anim cogn 15 : 797 - 806 . doi :
mean monthly rainfall ( mm ) for the period january 2003–december 2004 measured at the cape town international airport , cape town , south africa . solid bars denote rainfall measured during 2003 and hatched bars denote rainfall data measured during 2004 .
wild cape mole - rats had a slightly lower latency to find the escape holes than the captive animals on all days , although this was not significantly so . however , wild cape mole - rats made more errors in attaining the goal , although only on the second day this was significant . even with the higher number of wrong turns , wild mole - rats were still faster in finding the escape hole , implying that they are moving much faster than the captive mole - rats . the higher number of wrong entries of the wild mole - rats may again be a result of the speed at which the animals travel .
although it has a limited distribution , the cape dune mole - rat is listed as least concern because it is common within its range and survives successfully within environments modified by humans , such as agricultural areas . in some areas they are considered locally abundant and even a pest . there are no major threats to this species .
wild trapped cape mole - rats made significantly more entries into tunnels ( p = 0 . 027 ) and they visited a larger number of different tunnels ( p = 0 . 013 ) than laboratory - housed cape mole - rats . no difference was evident between the wild trapped and laboratory housed mole - rats in terms of latency to enter the first tunnel , total time spent in tunnels or the mean time spent in each tunnel ( table 1 ; figure 1 ) .
day . by day 4 , all animals reached the escape hole significantly faster than on day 1 . b . incorrect entries into blocked arms of wild cape mole - rats are higher on the 2
mcmahon , l . , and m . fraser . 1988 . a fynbos year . david philip , cape town .
webster db , webster m ( 1972 ) kangaroo rat auditory thresholds before and after middle ear reduction . brain behav evol 5 : 41–53
succession of follicles from primordial to graafian for female cape dune mole - rats captured from january 2003 to january 2004 . values are given as mean number of follicles ± se per section of ovarian tissue .
' ' the social behavior of the naked mole rat is one of the mammal finds of the century , ' ' said richard d . alexander , a university of michigan biologist who is one of the investigating scientists .
goldblatt , p . , and j . manning . 1998 . gladiolus in southern africa . fernwood press , cape town .
as explained more fully below , naked mole rats fulfill all three of these requirments .
no information could be found on predation in cape mole rats . it is likely that these animals do experience predation , probably by snakes , or by other animals capable of entering their burrows or digging them up .
l . hart , m . j . o ' riain , j . u . m . jarvis , n . c . bennett ; is the cape dune mole - rat , bathyergus suillus ( rodentia : bathyergidae ) , a seasonal or aseasonal breeder ? , journal of mammalogy , volume 87 , issue 6 , 29 december 2006 , pages 1078–1085 , urltoken
rupert a , moushegian g ( 1970 ) neuronal resonses of kangaroo rat ventral cochlear nucleus to low - frequency tones . exp neurol 26 : 84–102
avni r , tzvaigrach y , eilam d ( 2008 ) exploration and navigation in the blind mole rat ( spalax ehrenbergi ) : global calibration as a primer of spatial representation . j exp biol 211 : 2817 - 2826 . doi :
agroup of scientists studying the naked mole rat , a rare hairless rodent that lives in east africa , have recently found that the seldom - seen creature has one of the most bizarre social behavior patterns of any mammal in the animal kingdom .
goldblatt , p . , and p . manning . 2000 . plants of the cape flora . strelitzia 9 : 1 - 744 .
a . escape latency in the paddling y - maze shows that wild and laboratory cape mole - rats found the escape hole significantly faster on the 3 rd day compared to the 1 st day . by day 4 , all animals reached the escape hole significantly faster than on day 1 . b . incorrect entries into blocked arms of wild cape mole - rats are higher on the 2 nd day than for the laboratory animals on day 2 ( * )
his favourite species is the damaraland mole rat that lives mainly in the kalahari : “they are very vocal and when they huddle and you put your hand out , they sometimes think you are one of them and turn around and groom your hand . ”
evolution of eusociality in the bathyergidae . the case of the giant mole rats ( cryptomys mechowi )
jarvis jum , bennett nc ( 1991 ) ecology and behaviour of the family bathyergidae . in : sherman pw , jarvis jum , alexander rd ( eds ) the biology of the naked mole - rat . princeton university press , princeton new jersey , pp 66–96
there are a lot of fossils of heterocephalus , the lineage that included the naked mole - rat . these partial skulls - both from the pliocene of tanzania - represent the extinct species h . manthii ( at left ) and h . quenstedti ( from denys 2011 ) .
- although simpler than the social hierarchy of honeybees or ants , the organization of a naked mole rat colony requires both males and females to perform many specialized chores . these categories include food carriers , nest builders , garbage collectors , tunnel diggers and nursemaids to the queen .
cape mole rats produce an averag of 5 . 9 young per litter , although they may produce as few as 3 and as many as 10 . young are unfurred at birth , measure 30 to 40 mm , and weigh between 5 and 12 g .
johnson , s . j . 1996 . pollination , adaptation and speciation models in the cape flora of south africa . taxon 45 : 59 - 66 .
- one female , selected by methods still unknown , becomes the ' ' queen ' ' of the colony and , like the queen in a wasp colony , is the only breeding female in the community . the mole rat queen becomes much larger than other females in the colony .
naked mole rats are not threatened . they are widespread and numerous in the drier regions of east africa .
cowling , r . m . and d . m . richardson . 1995 . fynbos : south africa ' s unique floral kingdom . fernwood press , cape town
the cape dune mole - rat is the largest completely subterranean mammal in africa . the body is cylindrical covered in short thick fur , with short limbs and a tail . there is a stiff fringe of hair on the tail and on the outside edge of the hindfeet , this helps to control the soil while digging . adapted for digging , the eyes are small and there are no external ear pinnae . the nose is flat , with tough bare skin and valvular nostrils . one of the mole - rats most characteristic features are the large white protruding incisors . the lips close behind the grooved teeth , this stops the mole - rate from swallowing sand while digging or feeding . the feet have strong claws for digging .
breeding in cape mole rats occurs from august to december . males call the females by drumming with their hind feet . this drumming usually occurs in june and marks the beginning of the breeding period . gestation lasts 44 days . females experience a postpartum estrus and can produce two litters during the season .
the public should not think of mole rats as pests , as they contribute to soil aeration and the distribution of nutrients .
mole rats primarily expand their burrow system just after the rain when the dirt is soft and capable of being tunneled through .
in the exposure phase , wild and laboratory mole - rats did not perform differently with respect to time spent in either of the two initial arms of the maze , or the number of entries into each of the arms ( table 1 ) . in the test phase , visits of laboratory cape mole - rats in the novel arm were significantly longer than those of wild animals ( p = 0 . 032 ) . the cape mole - rats of the wild population were significantly more active than the laboratory animals entering all arms more often ( start arm : p = 0 . 044 ; 2 nd arm : p = 0 . 018 ; novel arm : p = 0 . 02 ) ( table 1 , figure 2 ) .
stuckenberg , b . r . 1962 . the distribution of the montane palaeogenic element in the south african invertebrate fauna . annals of the cape provincial museum 11 : 119 - 158 .
o ' riain has identified other changes that happen to a division of mole rats that he terms the defender mole rats . 17 the defender mole rats undergo several morphological specializations , including an increase in incisor width , an increase in jaw musculature , and the developement of a heterotrophied temporal musculature resulting in what is described as a ` ` square shaped head . ' ' 18
experimental procedures were approved by the animal use and care committee at the university of pretoria ( ec013 - 09 ) . a trapping permit was obtained from the western cape nature conservation authority .
wild cape mole - rats exhibited more variability in their behaviour than the laboratory conspecifics . a relationship between activity and anxiousness was observed in laboratory opossums , more active animals were less anxious , and likewise , more active animals showed more variable behaviour [ 22 ] . as a result of the more variable behaviour of the wild animals , differences in some of the behavioural measurements of the two groups appeared non - significant . the differences in activity between wild and laboratory housed cape mole - rats may be due to a shift from exploratory behaviour in the wild animals to a fearful or aggressive phenotype as has been described for other captive animals [ 23 ]
bennett nc , faulkes cg ( 2000 ) african mole - rats : ecology and eusociality . cambridge , uk : cambridge university press .
fluctuation in a ) seminiferous tubule diameter ( μm ) and b ) testosterone concentration ( nmol / liter ) in male cape dune mole - rats captured from january 2003 to january 2004 ( mean ± se ) . numbers of individuals used to determine the testosterone concentration are given in parentheses after the month in which they were captured .
johannesburg - after three decades of studying mole rats , award - winning professor of mammology nigel bennett says they still have mysteries to unlock .
daly , t . j . m . , williams , l . a . and buffenstein , r . , ( 1997 ) . catecholaminergic innervation of interscapular brown adipose tissue in the naked mole - rat ( heterocephalus glaber ) . journal of anatomy , 190 : 321 - 326 . doi : 10 . 1046 / j . 1469 - 7580 . 1997 . 19030321 . x
cowling , r . m . and c . e . heijnis . 2001 . broad habitat units as biodiversity entities for conservation planning in the cape floristic region . south african journal of botany ( in press )
cowling , r . m . and w . j . bond . 1991 . how small can reserves be ? an empirical approach in cape fynbos , south africa . biological conservation 58 : 243 - 56 .
naked mole rats ' substance p deficiency has also been tied to their lack of the histamine - induced itching and scratching behavior typical to rodents .
, which prevents cell division once a group of cells reaches a certain size . most mammals , including naked mole rats , have a gene called
picker , m . d . , and m . j . samways 1996 . faunal diversity and endemnicity of the cape peninsula , south africa – a first assessment . biodiversity and conservation 5 : 591 - 606 .
reichman , o . , j . jarvis . 1989 . the influence of three sympatric species of fossorial mole - rats ( bathyergidae ) on vegetation .
the first thing we have to say is that we’re talking specifically here about bathyergid mole - rats or blesmols , and bathyergid mole - rats or blesmols alone : other morphologically and ecologically similar rodent species are also called mole - rats , but they’re not part of bathyergidae . those species – they include the eurasian blind mole - rats of the genera nannospalax and spalax – are included within a group termed spalacinae or spalacidae . they appear to be muroids – part of the enormous rodent group that includes mice , rats , hamsters , voles , gerbils and so on – and hence are not even close to bathyergids .
assuming there are castes , there is some evidence suggesting that h . glaber displays age polyethism . jarvis ( ' 81 ) , still working in the assumption of distinct castes , suggested that all newborns , once weaned , enter into the frequent worker caste . faster growing mole - rats would quickly attain larger size and move into the infrequent worker caste , whereas slower growing mole - rats would continue in the frequent - worker caste , permanently . faster growing mole - rats also may go on to become breeders when the current queen dies . this is similar to what has been found about damarland mole - rats .
. it is more sensible that cape mole rats use seismic signals over auditory communication because seismic signals travel better and farther underground . it is not know how detection of seismic waves is accomplished in this species , although it is theorized that it is a form of bone conduction . vocal communication is used , but usually only when the animals are in close proximity to each other .
johnson , s . d . 1992 . plant - animal relationships . pages 175 - 205 in r . m . cowling , editor . the ecology of fynbos . nutrients , fire and diversity . oxford university press , cape town .
rebelo , a . v . 1992 . preservation of biotic diversity . pages 309 - 344 in r . m . cowling , editor . the ecology of fynbos . nutrients , fire and diversity . oxford university press , cape town .
burrowing through the ground , a single rodent will chisel the earth with its oversize front teeth and pack the walls of its tunnel by pushing with its snout . trailed by fellow workers , the mole rat at the front of the digging team throws earth between its legs backward to another worker who , acting like a dump truck , carries it to a worker at the rear end of the tunnel who kicks it outside into a pile .
reichman oj , jarvis jum ( 1989 ) the impact of three species of fossorial herbivorous mole - rats ( rodentia : bathyergidae ) on overlying vegetation . j mammal 70 : 763–771
we are much indebted to john and jeanette duckitt from waylands for allowing us to capture animals on their farms . hannah thomas is thanked for assistance with the collection of mole - rats . we thank the western cape nature conservation from south africa for issuing trapping permits . we would like to thank robert m . j deacon , oxford , for guidance in the experimental setup and hans welzl , zurich , for critical reading of the manuscript .
the first experiment was designed to test the exploratory behaviour and general activity levels of cape mole - rats . animals were placed in the centre of the box and observed for 3 minutes . the latency to enter the first tunnel , total number of entries , total and mean duration spent in tunnels and number of tunnels visited was recorded . all four feet of the animal were required to be inside a tunnel to be considered as an entry .
some mole rats are solitary , while others live socially , with a queen and “one or two male consorts” . the others in the colony either serve as frequent or infrequent workers .
is mainly a burrowing animal which spends most of its time underground . the incisors are used more for digging than are the claws . cape mole rats have extensive burrow systems that may underlie 5 to 10 percent of a field . mounds from excavation of soil may cover 8 to 20 percent of a field . the line of excavation is distinctly marked by the mounds formed where the earth has been thrown out of the burrow by the animal periodically .
cowling , r . m . and p . m . holmes . 1992 . flora and vegetation . pages 23 - 61 in r . m . cowling , editor . the ecology of fynbos . nutrients , fire and diversity . oxford university press , cape town .
trinder - smith , t . h . , r . m . cowling , and h . p . linder . 1996 . profiling a besieged flora : rare and endemic plants of the cape peninsula , south africa . biodiversity and conservation 5 : 575 - 589 .
although laboratory housed cape mole - rats explored both the open space and the tunnels in the tunnel maze , they were much less active compared to their wild counterparts . similarly , laboratory guinea pigs were also found to be less exploratory compared to their wild counterparts [ 19 ] . wild animals are generally considered as more exploratory and responsive to their environment than laboratory animals [ 20 ] , while some domesticated animals show a reduction in emotional reactivity [ 21 ] .
naked mole rats appear to have a high resistance to cancer ; cancer has never been observed in them . a potential mechanism that averts cancer is an
over - crowding
gene ,
honeycutt rl , edwards sv , nelson k , nevo e ( 1987 ) mitochondrial dna variation and the phylogeny of african mole rats ( rodentia : bathyergidae ) . syst zool 36 : 280–292
in the wild , naked mole - rats usually breed once a year , if the litter survives . in captivity , they breed all year long and can produce a litter every 80 days .
deacon rm , dulu td , patel nb ( 2012 ) naked mole - rats : behavioural phenotyping and comparison with c57bl / 6 mice . behav brain res 231 : 193 - 200 . doi :
dr . sherman and dr . alexander had observed naked mole rats in kenya and , with the help of dr . jarvis , collected a number of live specimens and brought them back to their respective laboratories at michigan and cornell for observation . in the labs , darkened to simulate underground conditions in the wild , nearly 200 mole rats scamper through a series of clear plastic tunnels and nesting areas .
african mole - rats represent an extensive adaptive radiation of subterranean rodents across sub - saharan africa . a recently revised estimate of biodiversity in the family suggests 30 or more species comprising six genera : eusocial
naked mole rats live in colonies that have an average of 80 members , although colonies with nearly 300 mole rats have been found . 3 this makes h . glaber colonies the largest of the social bathyergids . h . glaber share a burrow system and live togeather throughout the year , and they share the common needs of food foraging , defense , reproduction , burrow maintainence and care of the young .
clusters averaging 75 to 80 individuals live together in complex systems of burrows in arid african deserts . the tunnel systems built by naked mole rats can stretch up to two or three miles in cumulative length .
which does a similar task , but prevents cellular reproduction at a much later point than p16 does . the combination of p16 and p27 in naked mole rats cells is a double barrier to cell proliferation .
costanzo ms , bennett nc , lutermann h ( 2009 ) spatial learning and memory in african mole - rats : the role of sociality and sex . physiol behav 96 : 128 - 134 . doi :
the naked mole rat is well adapted for the limited availability of oxygen within the tunnels that are its habitat : its lungs are very small and its blood has a very strong affinity for oxygen , increasing the efficiency of oxygen uptake . it has a very low respiration and metabolic rate for an animal of its size , about 2 / 3 that of a mouse of the same size , thus using oxygen minimally . in long periods of hunger , such as a drought , its metabolic rate can be reduced by up to 25 percent .
divisions within the nonbreeding caste are less well substantiated . jarvis ( 81 ) reported observing three distinct worker castes in her mole - rat colonies . she labeled these frequent workers , infrequent workers ad non - workers . frequent workers were smaller , and did the lion ' s share of the work moving food , transporting soil and carrying children . infrequent workers spend more time resting in the sleeping den , but do work occasionally . non - workers however spend most of their time in the communal area helping to take care of the young .
deacon , h . j . , m . r . jury , and f . ellis . 1992 . selective regime and time . pages 6 - 22 in r . m . cowling , editor . the ecology of fynbos . nutrients , fire and diversity , oxford university press , cape town .
] . since mole - rats spend their entire life underground their visual system is regressed . although morphologically normal , their eyes are microphthalmic and the projections to all cns visual structures as well as the structures themselves are reduced to varying degrees . current data suggests that mole - rats have low visual acuity and only a crude capability to discriminate brightness and form , and their vision clearly is not suited for aboveground orientation [
the naked mole rat is one of the two species of mammals that exhibit eusociality . this eusocial structure is similar to that found in ants , termites , and some bees and wasps . only one female ( the queen ) and one to three males reproduce , while the rest of the members of the colony function as workers . the queen and breeding males are able to breed at one year of age . workers are sterile , with the smaller focusing on gathering food and maintaining the nest , while larger workers are more reactive in case of attack .
cowling , r . m . , p . m . holmes , and a . g . rebelo . 1992 . plant diversity and endemism . pages 62 - 112 in r . m . cowling , editor . the ecology of fynbos . nutrients , fire and diversity . oxford university press , cape town .
the fact that mole rats have regular circadian rhythms – despite the fact they are not exposed to light which normally governs these cycles of behavioural , psychological and physical changes in living organisms – was also of interest .
cowling , r . m . , p . m . holmes , and a . g . rebelo . 1992 . plant diversity and endemism . pp . 62 - 112 in r . m . cowling , editor . the ecology of fynbos . nutrients , fire and diversity . oxford university press , cape town .
they have found that unlike other species of mole rats , which are hairy and larger and live alone or in small family groups above ground , naked mole rats congregate in large underground colonies about a foot beneath the earth ' s surface . they create an extensive tunnel system with a large central nesting area . the animals are found mostly in open woodlands in kenya , ethiopia and somalia , and subsist on roots , tubers and bulbs .
blombos cave is a small cave on the southern cape coast , near still bay . in 1993 , chris henshilwood and cedric poggenpoel began excavations there , hoping to find a later stone age sequence that could serve as a reference sequence against which to compare material from a number of open sites already excavated in the vicinity .
jarvis , j . u . m . 2001 . african mole - rats . in macdonald , d . ( ed ) the new encyclopedia of mammals . oxford university press ( oxford ) , pp . 690 - 693 .
ovarian mass and volume . —the corrected mass of the ovaries of the cape dune mole - rat increased from january ( 0 . 40 ± 0 . 06 mg / g ) to a peak value in may ( 0 . 59 ± 0 . 1 mg / g ; fig . 3 ) . a gradual decrease then followed with lowest value obtained in october ( 0 . 25 ± 0 . 07 mg / g ) . from october to december the mass of the ovaries again increased to 0 . 37 ± 0 . 05 mg / g . ovarian volume was fairly stable throughout the year , ranging from 198 . 8 ± 19 . 6 mm 3 to 250 . 8 ± 17 . 4 mm 3 , except for april–june , when the volume of the ovaries was greatly reduced ( range 141 . 1 ± 16 . 00 mm 3 to 154 . 2 ± 13 . 20 mm 3 ; fig . 4 ) .
cowling , r . m . , r . l . pressey , a . t . lombard , c . e . heijnis , d . m . richardson , and n . cole . 1999 . framework for a conservation plan for the cape floristic region . ipc report 9902 submitted to world wide fund for nature , south africa .
cowling , r . m . and d . j . mcdonald . ( 1999 ) . local endemism and plant conservation in the cape floristic region . pages 64 - 86 in p . w . rundel , g . montenegro , and f . jaksic , editors . landscape degradation in mediterranean - climate ecosystems . springer - verlag , heidelberg .
cowling , r . m . and s . m . pierce . 1999 . cape floristic province . pages 218 - 227 in r . a . mittermeier , n . myers , and c . g . mittermeier , editors . hotspots . earth’s biologically richest and most threatened terrestrial ecoregions . cemex , mexico city and conservation international , washington dc .
. . . cape dune molerats to indicate human consumption ( henshilwood , 1997 ) and has been noted on human - consumed hyraxes from blombos cave ( badenhorst et al . , 2014 ) . surface modification and breakage patterns suggest that hyrax and other small mammal remains at kds are a result of human consumption and not raptors or carnivores . . . .
. . . the burnt specimens are the result of people making fires in the cave . in some instances , for example , the burnt premaxillae of cape dune molerat are the direct result of cooking ( henshilwood 1997 ) . it is very unlikely that the floor of the shelter would burn naturally , owing to the lack of organic cover . . . .
hystricomorph / ctenohystrican / entodacryan rodent montage . the groups shown here are cane rats , dassie rats , gundis , old world porcupines , african mole - rats and caviomorphs ( represented by the chinchillid lagidium ) . images from the tet zoo textbook project .
dune mole rats are solitary and aggressively territorial , each animal maintaining its own burrow system that is spaced apart from its neighbour . the animals rarely venture above ground , but are often forced above ground during the rainy season when the water table rises .
] . they inhabit sealed but dynamic burrow systems and rarely emerge aboveground . tunnels are extended or altered whenever the soil is soft enough , thus mostly after rains , in search of food sources . mole - rats are both physically and physiologically well adapted for life underground [
naked mole rats display limited division of labor between different castes . the largest and most substantiated caste division is between the reproductives and the non - reproductives . generally only one reproductive female is found per colony , although there have been instances where two females share the position .
remains of rodents and insectivores recovered from abbot ' s cave in the middelburg district , cape province , provide evidence of vegetation change during the 10th to early 20th century a . d . before the 17th century vegetation was sparse and the climate apparently arid with seasonally extreme temperatures . most equable conditions with good scrub and grass cover occurred during the 18th century at . . . [ show full abstract ]
crish sd , rice fl , park tj , comer cm ( 2003 ) somatosensory organization and behavior in naked mole - rats i : vibrissa - like body hairs comprise a sensory array that mediates orientation to tactile stimuli . brain behav evol 62 : 141 - 151 . doi :
o ' riain , m . j . and faulkes , c . g . , ( 2008 ) . african mole rats : eusociality , relatedness and ecological constraints . in j . korb and j . heinze ( eds . ) , ecology of social evolution , 207 - 223 . urltoken
at lower temperatures , they use behavioural thermoregulation , as when cold , naked mole rats huddle together or bask in the shallow , more sun - warmed parts of their burrow systems . conversely , when they get too hot , they retreat to the deeper , cooler parts of their tunnel system .
faulkes , c . g . , verheyen , e . , verheyen , w . , jarvis , j . u . m . & bennett , c . 2004 . phylogeography patterns of genetic divergence and speciation in african mole rats ( family : bathyergidae ) . molecular ecology 13 , 613 - 629 .
nemec p , cvekova p , benada o , wielkopolska e , olkowicz s et al . ( 2008 ) the visual system in subterranean african mole - rats ( rodentia , bathyergidae ) : retina , subcortical visual nuclei and primary visual cortex . brain . res bull 75 : 356 - 364 . doi :
naked mole rats appear to be a slight exception to this rule , as some morphological specializations can be seen in some of the majro roles held by individuals . the most elaborate and distinctive change happens in the the breeding female , whose body lengthens and becomes much larger when she dominates the rest of the colony .
in the laboratory at cornell , dr . sherman has found that a queen bears an average of about 10 pups per litter and has four litters a year . the mature animals vary in size and weigh from one - half ounce to two ounces . despite their small size , the mole rats live up to 10 years or more .
of the 26 genera of subteranian rodents , only the bathyergidae display a range of social behaviors that ranges from solitary independent living to cooperative breeding and eusociality . 1 of the social bathygergids , naked mole rats are some of the most social . eusociality is a term that refers to the social structures of animals that fulfill three requirements : 2
seney , m . l . , kelly , d . a . , goldman , b . d . , šumbera , r . & forger , n . g . 2009 . social structure predicts genital morphology in african mole - rats . plos one 4 ( 10 ) : e7477 . doi : 10 . 1371 / journal . pone . 0007477
together , examination of our data supports the hypothesis that b . suillus is a seasonal breeder and that the onset of reproduction correlates with the winter rainfall period . rainfall raises the soil moisture content and triggers the growth of belowground plant structures , both of which may provide the mole - rats with reliable external cues for recrudescence ( dennis and marsh 1997 ) .
. . . moreover , three mandibular fragments are more burnt on the anterior and buccal ( incisor ) portion than on the posterior or lingual ( molar ) region . this pattern of burning has been shown in cape dune molerats to indicate human consumption ( henshilwood , 1997 ) and has been noted on human - consumed hyraxes from blombos cave ( badenhorst et al . , 2014 ) . surface modification and breakage patterns suggest that hyrax and other small mammal remains at kds are a result of human consumption and not raptors or carnivores . . . .
chronic stress has been shown to impair recognition memory in rats [ 28 ] , but brief periods of stress immediately prior to spatial memory tests can even affect performance positively [ 8 ] . this seems to be the case in the laboratory mole - rats as they did show a preference for the novel arm in the experiment even though they appeared to be more stressed than their wild conspecifics .
did members of either of these two subterranean rodent lineages - tachyoryctes ( at left ) and / or spalax - somehow displace bathyergid mole - rats from areas where they once occurred ? tachyoryctes image by eduard rüppell , in public domain ( i can ' t believe there are no good tachyoryctes photos in the public domain ) . spalax image by vivan755 , cc by - sa 3 . 0 .
the young develop quickly . their eyes are open and the fur has grown in completely by the age of 9 days . by 17 days of age , young mole rats can eat solid food . siblings become aggressive to one another , and disperse from their home by 60 days of age . adult size is reached by the age of 260 days and young of the previous year breed before their first birthday .
at left , a molecular phylogeny of bathyergid mole - rats - note how old the heterocephalus divergence is , and how heterocephalus is the sister - taxon to the rest of the clade . the images at right show ( b ) fukomys , ( c ) heliophobius , and ( d ) heterocephalus . b and c by sharry goldman ; d by radim šumbera . entire image from seney et al . ( 2009 ) , cc .
in males there appear to be 2 distinct phases of maximal testosterone production and secretion , in june and august . the increase in testosterone may well be one of the mediating factors leading to the onset of hind - foot drumming and subsequent mating . male namaqua dune mole - rats similarly displayed 2 distinct peaks in testosterone production in august and october that coincided with hind - foot drumming in the field ( herbst et al . 2004 ) .
] ) . the distribution of these roots and tubers eaten by mole - rats varies with habitat . in mesic regions , these food resources are more uniformly distributed , whereas in xeric regions of low or unpredictable rainfall , the plants are arid - adapted and more widely dispersed , or occur in high - density clumps that are widely dispersed and patchily distributed . the afdh brings together these environmental constraints as an explanation for social evolution in the bathergidae (
. . . researchers have argued that some lsa accumulations of mole - rats were human derived ( particularly those that are < 5000 years old ) while msa accumulations were most likely collected by non - human predators . for instance , researchers contend that the mole - rats from lsa sites or strata at pancho ' s kitchen midden ( jerardino , 1998 ) , eland ' s bay cave ( klein and cruz - uribe , 1987 ) , dk1 ( schweitzer , 1979 ; avery et al . , 1997 ; klein and cruz - uribe , 2000 ) , bbc ( henshilwood , 1997 ) , byneskranskop 1 ( schweitzer and wilson , 1982 ) , and tortoise cave ( klein and cruz - uribe , 1987 ; robey , 1987 ) are probably human accumulated . in some cases , the evidence for human agency centers on the presence of cut and burned bone ( lsa portions of dk1 and bbc ) . . . .
retrieve them when they wander astray or are carried along by the movements of workers traveling through the central nest ; and carry the pups away in the case of alarm calls being sounded in another part of the nest . 20 additionally , mole - rats practice allocoprophagy , or the repeated consumption of feces . pups do not have the bacteria yet living in their digestive tract to allow them to digest food . so they eat the pre - digested feces of the other colony members . 21
testicular mass and volume . —the testicular mass of male cape dune mole - rats was stable from january to april , ranging from 0 . 42 ± 0 . 13 mg / g to 0 . 57 ± 0 . 31 mg / g ( fig . 3 ) . this was followed by a sharp increase to 1 . 22 ± 0 . 94 mg / g in july . testicular mass then finally decreased to a value of 0 . 58 ± 0 . 27 mg / g in december . the volume of the testes showed a dramatic increase from april ( 277 . 5 ± 48 . 9 mm 3 ) to may ( 546 . 0 ± 64 . 2 mm 3 ; fig . 4 ) . testicular volume also changed throughout the year in a pattern closely mirroring the testes mass changes . volume of the testes was fairly constant from january to april . a peak value in the volume of the testes was reached in july ( 758 . 4 ± 75 . 1 mm 3 ) . this was followed by a decrease in the volume to 509 . 7 ± 75 . 4 mm 3 in september . in october there was another increase in volume ( 645 . 7 ± 89 . 1 mm 3 ) followed by a gradual decrease during november and december ( 371 . 7 ± 89 . 4 mm 3 ) .
a more plausible explanation may be that the slower locomotion of the captive mole - rats may provide them the opportunity to investigate more accurately . the wild animals were more active , moved faster and showed strong thigmotaxis . in addition , they are unable to use visual cues for navigation as a result of their low visual acuity [ 13 ] . therefore they are more likely to miss a novel space when they are not running along the wall with the opening to the novel or unfamiliar arm . slow exploration may allow laboratory animals a longer integration time of stimuli , hence a more thorough inspection of the surroundings .
' ' the animal has hardly any vision , ' ' dr . alexander said in an interview , ' ' but we assume that it navigates around its tunnels by the feel of its whiskers and tail . it probably uses odor as a guide . ' ' he added that the queen usually has one or two dominant male consorts , although the worker castes are not sterile . ' ' this is a most unusual situation , ' ' he said , noting that the colonies are usually quite peaceful . ' ' naked mole rats are the only mammals with a caste that surrenders its breeding rights without constant friction or fighting . ' '
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clonorchis sinensis , the chinese liver fluke , is a human liver fluke belonging to the class trematoda , phylum platyhelminthes .

this parasite lives in the liver of humans , and is found mainly in the common bile duct and gall bladder , feeding on bile .

these animals , which are believed to be the third most prevalent worm parasite in the world , are endemic to japan , china , taiwan , and southeast asia , currently infecting an estimated 30,000,000 humans .

85 % of cases are found in china .

the infection called clonorchiasis generally appears as jaundice , indigestion , biliary inflammation , bile duct obstruction , even liver cirrhosis , cholangiocarcinoma ( cca ) , and hepatic carcinoma .

it is the most prevalent human trematode in asia , and is still transmitted in korea , china , vietnam and also russia , with 200 million people at constant risk .

recent studies have proved that it is definite cancer-causing agent in the liver ( carcinoma ) and bile duct ( cca ) .

for this reason the international agency for research on cancer has classed it as a group 1 biological carcinogen in 2009 .

clonorchis sinensis

there is sufficient evidence in humans for the carcinogenicity of chronic infection with clonorchis sinensis . chronic infection with clonorchis sinensis causes cholangiocarcinoma .
labels : bile duct cancer , c . sinensis , chinese liver fluke , clonorchis sinensis , trematodes
experimental studies on the second intermediate hosts of clonorchis sinensis iv . observations on the fate of metacercariae of clonorchis sinensis in the fish host , cultriculus eigenmanni
clonorchis sinensis collected from a naturally infected cat . semichon ' s acetocarmine stained .
cross - sectional and case - control studies on clonorchis sinensis infection and cholangiocarcinoma .
. histopathological changes of the liver after praziquantel treatment in clonorchis sinensis infected rabbits .
the host - parasite relations of clonorchis sinensis in the mouse - studies on the development of c . sinensis in mouse -
topmouth gudgeons , pseudorasbora parva , one of the second intermediat hosts of clonorchis sinensis .
production and deformation of clonorchis sinensis eggs during in vitro maintenance . - pubmed - ncbi
studies in experimental animals exposed to liver flukes ( opisthorchis viverrini and clonorchis sinensis ) .
there is limited evidence in experimental animals for the carcinogenicity of infection with clonorchis sinensis .
kim y . relationship between clonorchis sinensis infestation and cholangiocarcinom of the liver in korea .
studies on the experimental mode of infections of clonorchis sinensis . ii . experimental infection of clonorchis sinensis cercaria to fry of fresh water fishes 1964 december ; 2 ( 3 )
hong st . clonorchis sinensis . in : miliotis md , bier jw , editors .
the draft genome of the carcinogenic human liver fluke clonorchis sinensis . - pubmed - ncbi
a destroyed clonorchis sinensis by praziquantel treatment . only anterior part and the body margin remained .
[ from recognition to practice : the 140th anniversary of the discovery of clonorchis sinensis ] .
newly found endemic foci of clonorchis sinensis in kyungpook province , korea . - pubmed - ncbi
katja schulz changed the thumbnail image of
file : clonorchis sinensis 2 . png
.
the most common types of liver flukes are clonorchis sinensis , opisthorchis viverrini and opisthorchis felineus .
molecular cloning and characterization of vitelline precursor protein b1 from clonorchis sinensis . - pubmed - ncbi
molecular identification , immunolocalization , and characterization of clonorchis sinensis triosephosphate isomerase . - pubmed - ncbi
identification and characterization of micrornas in clonorchis sinensis of human health significance . - pubmed - ncbi
an amorphous egg of clonorchis sinensis longer than the typical ones . 33 um x 16 um .
an amorphous egg of clonorchis sinensis widerer than the typical ones . 27 um x 18 um .
view of a branch of the nakdong - gang , one of endemic area of clonorchis sinensis .
katja schulz added the english common name
chinese river fluke
to
clonorchis sinensis
.
fang yy , et al . current prevalence of clonorchis sinensis infection in endemic areas of china .
clonorchis sinensis : life cycle , intermediate hosts , transmission to man and geographical distribution in korea .
a new pcr - based approach indicates the range of clonorchis sinensis now extends to central thailand .
cell - free translational screening of an expression sequence tag library of clonorchis sinensis for novel antigen discovery .
no fasciola hepatica etc . ( the sheep and cattle kind ) are larger flukes than clonorchis sinensis .
clonorchiasis is an infection caused by a parasitic worm , the chinese liver fluke , or scientifically called clonorchis sinensis ( also known as opisthorchis sinensis ) .
clonorchis sinensis adult worms ( about 2900 ) recovered from a heavy infected case during surgery of gall bladder .
muto s : on the primary intermediate host of clonorchis sinensis . chuo igakakai zasshi 25 : 49–52 , 1918
studies on the experimental mode of infections of clonorchis sinensis . iii . studies on the wormicidal effect of external mucous substance of some fresh water fish on the larva of clonorchis sinensis 1964 december ; 2 ( 3 )
pcr products on clonorchis sinensis eggs . m , dna marker ; lanes 1 - 5 , pcr amplicons ; lane 6 , negative control . the arrow on the right side represents the amplicon of clonorchis sinensis eggs .
experimental studies on the second intermediate hosts of clonorchis sinensis . iii . observations on the relationship between clavate cells of epidermis and infectivity of metacercariae of clonorchis sinensis in fresh - water fish 1974 december ; 12 ( 2 )
clonorchis sinensis provoked thickening of biliary epithelium , in which a blood vessel was generated . h & e stained .
[ from recognition to practice : the 140th anniversary of the discovery of clonorchis sinensis ] . - pubmed - ncbi
choi dw . clonorchis sinensis : life cycle , intermediate hosts , transmission to man and geographical distribution in korea .
artifactual finding clonorchis sinensis ( 400x mag ) . from public health image library ( phil ) . [ 5 ]
[ prevalence of clonorchis sinensis infection and effect of albendazole treatment among residents in two communities of zhongshan city ] .
chun sk . [ studies on the experimental mode of infections of clonorchis sinensis : ii . experimental infection of clonorchis sinensis cercaria to fry of fresh water fishes ] . korean j parasitol 1964 ; 2 ( 3 ) : 137–147 .
clonorchiasis , or chinese liver fluke disease , is caused by infection with clonorchis sinensis . adult c . sinensis flukes may measure up to 20 mm x 5 mm .
cho py , kim ti , whang sm , hong s - j . gene expression profile of clonorchis sinensis metacercariae .
clonorchis sinensis : life cycle , intermediate hosts , transmission to man and geographical distribution in korea . - pubmed - ncbi
a new pcr - based approach indicates the range of clonorchis sinensis now extends to central thailand . - pubmed - ncbi
cell - free translational screening of an expression sequence tag library of clonorchis sinensis for novel antigen discovery . - pubmed - ncbi
sun t : pathology and immunology of clonorchis sinensis infection in the liver . am clin lab sci 14 : 208–215 , 1984
hong st , kho wg , kim wh , et al . turnover of biliary epithelial cells in clonorchis sinensis infected rats .
park gm . genetic comparison of liver flukes , clonorchis sinensis and opisthorchis viverrini , based on rdna and mtdna gene sequences .
the carcinogenic liver fluke , clonorchis sinensis : new assembly , reannotation and analysis of the genome and characterization of tissue transcriptomes .
genetic diversity of clonorchis sinensis ( trematoda : opisthorchiidae ) in the russian southern far east based on mtdna cox1 sequence variation .
adult clonorchis sinensis , acetocarmine stained . its uterus is full of eggs , ovary and two tandem branched testes are seen well .
goh yh . acquired immunity in albino rats to clonorchis sinensis . korean j parasitol 1969 ; 7 ( 1 ) : 32–41 .
mcfadzen ajs , yeung rtt : acute pancreatitis due to clonorchis sinensis . trans r soc trop med hyg 60 : 466 , 1966
geographical variation of the liver fluke , clonorchis sinensis , from korea and china based on the karyotypes , zymodeme and dna sequences .
[ 2 ] park , d . h . and h . y . son . “images in clinical medicine : clonorchis sinensis . ”
park gm , im k - i , huh s , yong t - s . chromosomes of the liver fluke , clonorchis sinensis .
shim hs , lim bj , kim mj , et al . [ mucinous cholangiocarcinoma associated with clonorchis sinensis infestation : a case report ]
min , hk ( 1984 ) . clonorchis sinensis : pathogenesis and clinical features of infection . arzneimittelforschung . 34 , 1151 - 1153 .
chun sk . [ studies on the experimental mode of infections of clonorchis sinensis : iii . studies on the wormicidal effect of external mucous substance of some fresh water fish on the larva of clonorchis sinensis ] . korean j parasitol 1964 ; 2 ( 3 ) : 148–158 .
choi d , lim jh , lee kt , et al . cholangiocarcinoma and clonorchis sinensis infection : a case - control study in korea .
lim mk , ju yh , franceschi s , et al . clonorchis sinensis infection and increasing risk of cholangiocarcinoma in the republic of korea .
rhee jk . [ experimental studies on the second intermediate hosts of clonorchis sinensis : iii . observations on the relationship between clavate cells of epidermis and infectivity of metacercariae of clonorchis sinensis in fresh - water fish ] . korean j parasitol 1974 ; 12 ( 2 ) : 101–110 .
venom allergen - like protein 28 in clonorchis sinensis : four epitopes on its surface and the potential role of cys124 for its conformational stability .
metaplasia of mucin - secreting cells ( red ) in the bile duct mucosa of a rabbit infected with clonorchis sinensis . pas stained , x300 .
liu ys , chen m ( 1998 ) . biology of clonorchis sinensis and control of clonorchiasis [ in chinese ] . beijing : science press .
lee jh , rim hj , bak ub . effect of clonorchis sinensis infection and dimethylnitrosamine administration on the induction of cholangiocarcinoma in syrian golden hamsters .
micrograph depicts an egg of the parasitic trematode , or flatworm , clonorchis sinensis . from public health image library ( phil ) . [ 5 ]
genetic diversity of clonorchis sinensis ( trematoda : opisthorchiidae ) in the russian southern far east based on mtdna cox1 sequence variation . - pubmed - ncbi
clonorchiasis is an infection caused by a parasitic worm , the chinese liver fluke , or scientifically called clonorchis sinensis ( also known as opisthorchis sinensis ) . the term “fluke” means flatfish , since these parasites are flat
metaplasia of acid mucin - secreting cells ( blue ) in the bile duct mucosa of the clonorchis sinensis infected rabbit . alcian blue stained , x150 .
lee jh , yang hm , bak ub , rim hj . promoting role of clonorchis sinensis infection on induction of cholangiocarcinoma during two - step carcinogenesis .
geographical variation of the liver fluke , clonorchis sinensis , from korea and china based on the karyotypes , zymodeme and dna sequences . - pubmed - ncbi
csrn1 , a novel active retrotransposon in a parasitic trematode , clonorchis sinensis , discloses a new phylogenetic clade of ty3 / gypsy - like ltr retrotransposons .
chronological change in ratio of length to width of clonorchis metacercariae detected in cultriculus eigenmanni .
wykoff de . studies on clonorchis sinensis . iv . production of eggs in experimentally infected rabbits . j parasitol 1959 ; 45 ( 1 ) : 91–94 .
the carcinogenic liver fluke , clonorchis sinensis : new assembly , reannotation and analysis of the genome and characterization of tissue transcripto . . . - pubmed - ncbi
a metacercaria of clonorchis sinensis . the larva in the cyst wall is actively moving . note two suckers and a excretory bladder filled with dark granules . x150 .
the persistence of clonorchis sinensis infestation of the bile duct for a period of at least 26 years without neoplasia supervening is reported in a chinese immigrant to australia .
kim sh , park yn , yoon ds , et al . composite neuroendocrine and adenocarcinoma of the common bile duct associated with clonorchis sinensis : a case report .
lee jh , rim hj , sell s . heterogeneity of the “oval - cell” response in the hamster liver during cholangiocarcinogenesis following clonorchis sinensis infection and dimethylnitrosamine treatment .
hou , pc ( 1956 ) . relationship between primary carcinoma of the liver and infestation with clonorchis sinensis . j pathol bacteriol . 72 , 239 - 246 .
an egg from the oriental , or chinese liver fluke , clonorchis sinensis ( 400x mag ) . from public health image library ( phil ) . [ 5 ]
metacercariae of clonorchis sinensis collected from digested fish . the cyst wall is elliptical 0 . 16 - 0 . 20 mm long . dark granules are in the bladder .
kim yj , choi mh , hong st , bae ym . resistance of cholangiocarcinoma cells to parthenolide - induced apoptosis by the excretory - secretory products of clonorchis sinensis .
the wormicidal substance of fresh water fishes on clonorchis sinensis iv . preliminary research on the wormicidal substance from mucus of cyprinus carpio nudus 1983 june ; 21 ( 1 )
hong , s - t , and fang , y ( 2012 ) . clonorchis sinensis and clonorchiasis , an update . parasitol int . 61 , 17 - 24 .
qiao , t , ma , rh , and luo , xb ( 2012 ) . cholecystollithiasis is associated with clonorchis sinensis infection . plos one . 7 , e42471 .
wang yz ( 1983 ) clonorchis sinensis . in : human parasitology [ in chinese ) . zhao hx , editor . beijing : people health press , pp . 451–63 .
lee js , lee j , park s - j , yong t - s . analysis of the genes expressed in clonorchis sinensis adults using the expressed sequence tag approach .
patients with signs and symptoms of clonorchis infection or liver disease should see a health care provider .
the patient was treated with praziquantel for a bile duct disorder that was probably caused by clonorchis sinensis ( chinese liver fluke ) infection . her gastrointestinal symptoms responded to treatment .
hong st , fang y . clonorchis sinensis and clonorchiasis , an update . parasitol int . 2012 mar . 61 ( 1 ) : 17 - 24 . [ medline ] .
the intrahepatic bile duct of an experimentally infected rabbit with clonorchis sinensis , one year after treatment . note the persistent duct wall thickening but resolved inflammation , mucosal hyperplasia and lumen dilatation .
iida h . experimental study of the effects of clonorchis sinensis infection on induction of cholangiocarcinoma in syrian golden hamsters administered 0 . 03 % n - 2 - fluorenylacetamide ( faa ) .
jang jj , cho kj , myong nh , chai jy . enhancement of dimethylnitrosamine - induced glutathione s - transferase p - positive hepatic foci by clonorchis sinensis infestation in f344 rats .
kim , ti , na , bk , and hong , sj ( 2009 ) . functional genes and proteins of clonorchis sinensis . korean j parasitol . 47 , s59 - 68 .
choi , yk , yoon , bi , and won , ys ( 2003 ) . cytokine responses in mice infected with clonorchis sinensis . parasitol res . 91 , 87 - 93 .
csrn1 , a novel active retrotransposon in a parasitic trematode , clonorchis sinensis , discloses a new phylogenetic clade of ty3 / gypsy - like ltr retro . . . - pubmed - ncbi
a grass carp ( ctenopharyngodon idellus ) that are common hosts for c . sinensis
figure 2 . the three - host sequence life cycle of c . sinensis .
[ 3 ] eckroad , e . and h . lee . 2001 .
clonorchis sinensis .
animal diversity web . online . accessed 24 feb . 2012 . < urltoken > .
it is well established that guinea pig , rabbit and rat are equally susceptible to experimental infection with the chinese liver fluke , clonorchis sinensis . however , little work has been done on the studies of the host - parasite relationships between the liver fluke and mouse host . the experiments were undertaken to investigate the susceptibility , development and sexual maturity of clonorchis sinensis in mouse host .
park , gm ( 2007 ) . genetic comparison of liver flukes , clonorchis sinensis and opisthorchis viverrini based on rdna and mtdna gene sequences . parasitol res . 100 , 351 - 357 .
to cite this page : eckroad , e . and h . lee 2001 .
clonorchis sinensis
( on - line ) , animal diversity web . accessed july 09 , 2018 at urltoken
komiya y , kawana - tajimi t . the development of the excretory system of clonorchis sinensis in its definitive host . jpn j med sci biol 1953 ; 6 ( 6 ) : 571–575 .
the egg of a clonorchis sinensis ( commonly : human liver fluke ) , which contains the miracidium that develops into the adult form , floats in freshwater until it is eaten by a snail .
artifactual finding , which resembles a trematode egg of the chinese , or oriental liver fluke , clonorchis sinensis ( 400x mag ) . from public health image library ( phil ) . [ 5 ]
11 . klemencic s , phelan m , patrick r , vahdat n . oriental cholangiohepatitis ( clonorchiasis infestation ) caused by clonorchis sinensis . j emerg med 2012 ; 43 : e107 - 9 .
c . sinensis collected from a naturally infected cat . semichon ' s acetocarmine stained .
contigs and singlets of the assembled c . sinensis est pool according to developmental stage .
light microscopic changes of c . sinensis eggs in different solutions and media during cultivation .
deformed c . sinensis eggs observed after 90 days of incubation in different broth media .
the genomic structures of o . viverrini and c . sinensis have not been reported .
kim yj , choi mh , hong st , bae ym . proliferative effects of excretory / secretory products from clonorchis sinensis on the human epithelial cell line hek293 via regulation of the transcription factor e2f1 .
shin hr , lee cu , park hj , et al . hepatitis b and c virus , clonorchis sinensis for the risk of liver cancer : a case - control study in pusan , korea .
clonorchis infection can be prevented by avoiding raw or undercooked freshwater fish . lightly salted , smoked , or pickled fish can contain infectious parasites . clonorchis infection does not result from drinking river water or other non - potable water .
an intrahepatic bile duct of a rabbit infected with clonorchis sinensis . the bile duct showes severe papillary and glandular hyperplasia of the mucosa , dilatation , and periductal fibrosis and inflammation . he stained , x60 .
kim em , kim js , choi mh , et al . effects of excretory / secretory products from clonorchis sinensis and the carcinogen dimethylnitrosamine on the proliferation and cell cycle modulation of human epithelial hek293t cells .
csaes of neuro - receptors and neurotransmitter producing enzymes according to c . sinensis developmental stage .
rhee jk , kim pg , baek bk , lee sb , ahn bz . [ experimental infection of clonorchis sinensis to cyprinus carpio nudus ] . korean j parasitol 1983 ; 21 ( 1 ) : 11–19 .
choi , d , lim , jh , and lee , kt ( 2006 ) . cholangiocarcinoma and clonorchis sinensis infection : a care - control study in korea . j hepatol . 44 , 1066 - 1073 .
maeng , a , lee , hw , and bashir , q ( 2016 ) . oxidative stress - mediated mouse liver lesions caused by clonorchis sinensis infection . int j parasitol . 46 , 195 - 204 .
wykoff de . studies on clonorchis sinensis . iii . the host - parasite relations in the rabbit and observations on the relative susceptibility of certain laboratory hosts . j parasitol 1958 ; 44 ( 5 ) : 461–466 .
li g , he x , saidu k . epidemiology and control of clonorchiasis sinensis in china .
figures given are of raw temporary specimens of the metacercariae of clonorchis sinensis detected in the fish body , cultriculus eigenmanni . and , magnification on figures 2 , 3 and 6 is 200 times and remainder is 400 times .
yoo , wg , kim , d - w , and ju , j - w ( 2011 ) . developmental transcriptomic features of the carcinogenic liver fluke , clonorchis sinensis . plos neg trop dis . 5 , e1208 .
opisthorchis viverrini ( o . viverrini ) and clonorchis sinensis ( c . sinensis ) are pathologically important foodborne members of the genus opisthorchis ; family , opisthorchiidae ; order , digenea ; class , trematoda ; phylum , platyhelminths ; and kingdom , animalia . they belong to the same genus ( opisthorchis ) but to different species based on morphology ; nonetheless , the genus clonorchis is so well established in the medical literature that the term is retained here .
citation : uddin mh , bae ym , choi m - h , hong s - t ( 2012 ) production and deformation of clonorchis sinensis eggs during in vitro maintenance . plos one 7 ( 12 ) : e52676 . urltoken
lim , mk , ju , yh , and franceschi , s ( 2006 ) . clonorchis sinensis infection and increasing risk of cholangiocarcinoma in the republic of korea . am j trop med hyg . 75 , 93 - 96 .
pak , jh , kim , ik , and kim , sm ( 2014 ) . induction of cancer - related microrna expression profiling using excretory - secretory products of clonorchis sinensis . parasitol res . 113 , 4447 - 4455 .
human infection with clonorchis sinensis is still a big public health problem in guangzhou . to investigate the correlation between clonorchiasis and climatic factors , we analyzed the clonorchiasis reported cases and simultaneous meteorological data during 2006–2012 in guangzhou city , china .
13 . hong st , choi mh , kim ch , chung bs , ji z . the kato - katz method is reliable for diagnosis of clonorchis sinensis infection . diagn microbiol infect dis 2003 ; 47 : 345 - 347 .
phylogenetic evolution of 50 conserved mirna families in clonorchis sinensis . ( a ) phylogenetic distribution of 50 conserved mirna families of c . sinensis . a plus ( + ) symbol indicates this mirna family exists in the species named on the left . ( b and c ) phylogenetic analysis of mir - 2 family shows middle evolution approach of mirna in c . sinensis . ( d and e ) phylogenetic analysis of mir - 87 family shows another evolution approach of mirna in c . sinensis which is conserved in middle and changed in the tail .
qian mb , chen yd , fang yy , tan t , zhu tj , zhou ch , wang gf , xu lq , zhou xn . epidemiological profile of clonorchis sinensis infection in one community , guangdong , people’s republic of china .
huang , s - y , zhao , g - h , and fu , b - q ( 2012 ) . genomics and molecular genetics of clonorchis sinensis : current status and perspectives . parasitol int . 61 , 71 - 76 .
lim , mk , ju , y - h , and franceschi , s ( 2006 ) . clonorchis sinensis infection and increasing risk of cholangiocarcinoma in the republic of korea . am j trop med hyg . 75 , 93 - 96 .
kim , yj , choi , mh , and hong , st ( 2009 ) . resistance of cholangiocarcinoma cells to parthenolide - induced apoptosis by the excretory - secretory products of clonorchis sinensis . parasitol res . 104 , 1011 - 1016 .
pak , jh , kim , d - w , and moon , jh ( 2009 ) . differential gene expression profiling in human cholangiocarcinoma cells treated with clonorchis sinensis excretory - secretory products . parasitol res . 104 , 1011 - 1016 .
pak , jh , moon , jh , and hwang , sj ( 2009 ) . proteomic analysis of differentially expressed proteins in human cholangiocarcinoma cells treated with clonorchis sinensis excretory - secretory products . j cell biochem . 108 , 1376 - 1388 .
the 30 most abundantly expressed genes in the adult , metacercaria , and egg stages of c . sinensis .
the number of worms found in each group mice experimentally infected with various number of metacercaria of c . sinensis
measurements of the well developed worms of c . sinensis selected at various developmental stages ( unit : mm )
fresh adult worms of clonorchis sinensis recovered from experimentally infected rabbits . worms in the right side are 4 weeks old and those in the left are 12 weeks old . the worm is grossly red but the intestinal ceca and distal uterus are dark .
rim , hj , lyu , ks , and lee , js ( 1981 ) . clinical evaluation of the therapeutic efficacy of paraziquantel ( embay 8440 ) against clonorchis sinensis infection in man . ann trop med parasitol . 75 , 27 - 33 .
ju , jw , joo , hn , and lee , mr ( 2009 ) . identification of a serodiagnostic antigen , legumain , by immunoproteomic analysis of excretory - secretory products of clonorchis sinensis adult worms . proteomics . 9 , 3066 - 3078 .
kim em , verweij jj , jalili a , et al . detection of clonorchis sinensis in stool samples using real - time pcr . ann trop med parasitol . 2009 sep . 103 ( 6 ) : 513 - 8 . [ medline ] .
length distribution of small rnas from clonorchis sinensis identified and analyzed by deep sequencing . analysis of 12 , 138 , 350 high quality reads after filtering low quality tags , 5 ' and 3 ' adaptor and contamination formed by adaptor - adaptor ligation .
park , g . m . , & yong , t . s . ( 2003 ) . effects of gamma - irradiation on the infectivity and chromosome aberration of clonorchis sinensis . korean journal of parasitology , 41 ( 1 ) , 41 - 45 .
clonorchiasis is a foodborne infection caused by clonorchis sinensis or chinese liver fluke , a parasitic worm which grows and resides in the bile ducts of the liver in humans and fish - eating mammals . it is acquired by eating freshwater fish containing the fluke larvae
figure a : c . sinensis egg : the small knob at the abopercular end is visible in this image .
opisthorchis viverrini and clonorchis sinensis were considered by a previous iarc working group in 1994 ( iarc , 1994 ) . since that time , new data have become available , these have been incorporated in the monograph , and taken into consideration in the present evaluation .
rhee jk , lee sb , ahn bz . [ the wormicidal substance of fresh water fishes on clonorchis sinensis v . purification and chemical characterization of clonorchicidal substance from epidermal mucus of cyprinus carpio ] . korean j parasitol 1984 ; 22 ( 1 ) : 127–134 .
xu y , chen w , bian m , wang x , sun j , sun h , jia f , liang c , li x , zhou x , huang y , yu x . molecular characterization and immune modulation properties of clonorchis sinensis - derived rnaset2 .
jeong , y - i , shin , h - e , and lee , s - e ( 2016 ) . prevalence of clonorchis sinensis infection among residents along 5 major rivers in the republic of korea . korean j parasitol . 54 , 215 - 221 .
yang , q - l , shen , j - q , and xue , y ( 2015 ) . pathological lesions and inducible nitric oxide synthase expressions in the liver of mice experimentally infected with clonorchis sinensis . korean j parasitol . 53 , 777 - 783 .
clonorchis sinensis causes clonorchiasis , which is endemic to korea , china , taiwan and vietnam ; approximately 15 million people are estimated to be infected [ 1 ] – [ 3 ] . c . sinensis is a significant pathogen both from an epidemiological and clinical perspective , as people who develop clonorchiasis are debilitated , thereby negatively impacting socio - economic activities . in c . sinensis endemic areas , inhabitants become infected by eating raw or inappropriately cooked fresh water fish caught from water bodies near their villages [ 4 ] . fresh water fish are the hosts of c . sinensis metacercariae , which is the infective stage to humans .
kim , yj , choi , mh , and hong , st ( 2008 ) . proliferative effects of excretory / secretory products from clonorchis sinensis on the human epithelial cell line hek293 via regulation of the transcription factor e2f1 . parasitol res . 102 , 411 - 417 .
kim , em , bae , ym , choi , mh , and hong , st ( 2012 ) . cyst formation , increased anti - inflammatory cytokines and expression of chemokines support for clonorchis sinensis infection in fvb mice . parasitol int . 61 , 124 - 129 .
parvathi a , sanath kumar h , kenchanna prakasha b , et al . clonorchis sinensis : development and evaluation of a nested polymerase chain reaction ( pcr ) assay . exp parasitol . 2007 mar . 115 ( 3 ) : 291 - 5 . [ medline ] .
clonorchis sinensis is a carcinogenic human liver fluke that is widespread in asian countries . increasing infection rates of this neglected tropical disease are leading to negative economic and public health consequences in affected regions . experimental and epidemiological studies have shown a strong association between the incidence of cholangiocarcinoma and the infection rate of c . sinensis . to aid research into this organism , we have sequenced its genome .
figure b : bithynia sp . , another common intermediate host of c . sinensis . image courtesy of michal maňas .
species identification of h . taichui , o . viverrini and c . sinensis using pcr and pcr - rflp analysis .
rhee jk , baek bk , ahn bz , park yj . [ the wormicidal substances of fresh water fishes on clonorchis sinensis : i preliminary research on the wormicidal substance from mucous substance of carassius carassius ] . korean j parasitol 1979 ; 17 ( 2 ) : 121–126 .
yan , c , li , x - y , and li , b ( 2015 ) . expression of toll - like receptor ( tlr ) 2 and tlr4 in the livers of mice infected by clonorchis sinensis . j infect dev ctries . 9 , 1147 - 1155 .
nam , j - h , moon , jh , and kim , ik ( 2012 ) . free radicals enzymatically triggered by clonorchis sinensis excretory - secretory products cause nf - κb - mediated inflammation in human cholangiocarcinoma cells . int j parasitol . 42 , 103 - 113 .
uddin , mh , choi , mh , and kim , wh ( 2015 ) . involvement of psmd10 , cdk4 and tumor suppressors in development of intrahepatic cholangiocarcinoma of syrian golden hamsters induced by clonorchis sinensis and n - nitrosodimethylamine . plos negl trop dis . 9 , e0004008 .
which trematode may cause serious disease , with loads of over 25 , 000 parasites per patient ? if you answered the clonorchis sinensis , you are correct ! clonorchis sinensis , also known as the chinese liver fluke , lives in the liver of humans and is commonly found in the bile ducts and gall bladder [ 1 ] . the geographic distribution of this parasite is in endemic areas in asia including china , japan , korea , taiwan , and vietnam [ 1 ] . it is found mainly in asian immigrants , or following ingestion of imported , undercooked , or pickled freshwater fish . c . sinensis has also been reported in non - endemic areas including the united states .
clonorchis sinensis infections are endemic in japan , korea , vietnam , and china . in addition to infecting humans , clonorchis can also infect dogs and cats . opisthorchis felineus , a closely related species of trematode that infects various carnivores including humans , occurs throughout the philippines , india , japan , vietnam , and eastern europe , particularly poland and western russia . o . viverini is found in northern thailand 1 and in laos . 2 the biology , pathogenesis , and clinical disease of all three species are so similar that only c . sinensis is discussed here .
iarc working group on the evaluation of carcinogenic risk to humans . biological agents . lyon ( fr ) : international agency for research on cancer ; 2012 . ( iarc monographs on the evaluation of carcinogenic risks to humans , no . 100b . ) opisthorchis viverrini and clonorchis sinensis .
kim , em , kim , js , and choi , mh ( 2008 ) . effects of excretory / secretory products from clonorchis sinensis and the carcinogen dimethylnitrosamine on the proliferation and cell cycle modulation of human epithelial hek293t cells . korean j parasitol . 46 , 127 - 132 .
figure b : c . sinensis egg . note the operculum resting on
shoulders ;
image taken at 400× magnification .
chen , m . , lu , y . , hua , x . , & mott , k . e . ( 1994 ) . progress in assessment of morbidity due to clonorchis sinensis infection : a review of recent literature . tropical disease bulletin , 91 , r7 - 65 .
li , s . , kang , h . w . , choi , m . h . , & hong , s . t . ( 2006 ) . long - term storage of clonorchis sinensis metacercariae in vitro . parasitology research , 100 ( 1 ) , 25 - 29 .
jeong , y - i , kim , sh , and ju , jw ( 2011 ) . clonorchis sinensis - derived total protein attenuates airway inflammation in murine asthma model by inducing regulatory t cells and modulating dendritic cell functions . biochem biophys res comm . 407 , 793 - 800 .
kim , d - w , kim , j - y , and moon , jh ( 2010 ) . transcriptional induction of minichromosome maintenance protein 7 ( mcm7 ) in human cholangiocarcinoma cells treated with clonorchis sinensis excretory - secretory products . mol biochem parasitol . 173 , 10 - 16 .
cdc . gov . cdc - clonorchis - frequently asked questions ( faqs ) . 2015 . available at : urltoken ( accessed on 01 / 30 / 2015 )
rhee jk , baek bk , ahn bz , park yj . [ the wormicidal substances of fresh water fishes on clonorchis sinensis : ii . preliminary research on the wormicidal substances from mucous substances of various fresh water fishes ] . korean j parasitol 1980 ; 18 ( 1 ) : 98–104 .
nishimura in 1943 indicated for the first time that a serious endemic focus of clonorchis sinensis is located in the vicinity of yeong - cheon ( kyungpook province , korea ) . later , numerous surveys of this fluke in the province have been made , but no additional report on the endemic focus of the fluke has been available . the overall percentage of clonorchis sinensis infections , based on the discovery of eggs by the formalin - ether sedimentation technique , was found to be 54 . 8 percent from 851 residents in nakjeon ri ( village ) , danmil myun , uiseong gun ( county ) , kyungpook province and no significant difference was observed in the sex specific rate of the individuals infected . there is a high incidence of infection with clonorchis sinensis . the infection rate in the age group from 0 to 4 years was 14 . 6 per cent , 5 to 9 years was 35 . 7 per cent and 10 to 14 years was 51 . 7 per cent . in the worn burdens for residents , the average number of egg - counts was 41 , 800 . it is found that a serious endemic focus of clonorchis sinensis exists in the vicinity of nakjeon village .
rates of infection and recovery and average worm burden in each group of mice , experimentally infected with the metacercariae of c . sinensis
other sections abstract introduction life cycle of c . sinensis , symptoms , diagnosis and epidemiology pathogenesis and carcinogenesis concluding remarks acknowledgements figures references
rhee jk , kim pg , baek bk , lee sb , ahn bz . [ the wormicidal substance of fresh water fishes on clonorchis sinensis : iv . preliminary research on the wormicidal substance from mucus of cyprinus carpio nudus ] . korean j parasitol 1983 ; 21 ( 1 ) : 21–26 .
foodborne trematodiases are caused by trematode worms ( “flukes” ) , among them the species affecting humans with potentially severe outcomes , are clonorchis , opisthorchis , fasciola and paragonimus .
diagnosis of clonorchis infection is based on microscopic identification of eggs in stool specimens . more than one stool sample may be needed to detect the eggs . the eggs of clonorchis are very similar to those of opisthorchis , another liver fluke , but can be distinguished by microscopic features . additionally , cysts containing the parasite can sometimes be detected by ultrasound , ct , or mri . serologic testing ( testing the blood ) for clonorchis is not useful for patient management and is not available in the united states .
citation : yoo wg , kim d - w , ju j - w , cho py , kim ti , cho s - h , et al . ( 2011 ) developmental transcriptomic features of the carcinogenic liver fluke , clonorchis sinensis . plos negl trop dis 5 ( 6 ) : e1208 . urltoken
zhang , h . , lee , c . - . , li , s . , choi , m . - . , & hong , s . - . ( 2003 ) . lethal effect of ammonia on metacercariae of clonorchis sinensis . parasitology research , 90 ( 5 ) , 421 - 422 .
kang , j - m , ju , h - l , and lee , j ( 2015 ) . mapping the putative epitope domain of clonorchis sinensis paramyosin ( cs pmy ) recognized by cs pmy - specific immunoglobulin g in sera of human clonorchiasis . mol biochem parasitol . 201 , 66 - 71 .
clonorchis sinensis is the major liver fluke found in p . r . china , especially in the northeastern provinces of heilongjiang and jilin ( ministry of health china , 2005 ) , as well as in neighbouring regions of both north and south korea ( hotez , 2003 ; kim et al . , 2009 ) .
( figure 3 ) section of c . sinensis in the bile duct . note the thickening of the bile duct walls ( * ) .
functional categorization of genes and protein domains of c . sinensis . ( a ) proportions of the 9 , 371 c . sinensis proteins in different gene ontology categories ( biological process terms only ) . the classification was carried out by categorizer [ ] based on the second level of the gene ontology category biological process . ( b ) 8 , 371 domains were detected in c . sinensis , vertebrates ( h . sapiens , g . gallus and d . rerio ) , d . melanogaster , c . elegans and schistosoma ( s . japonicum and s . mansoni ) . the major protein domains of c . sinensis are shared with other taxa and c . sinensis has the fewest unique domains .
i am a chinese student living in california . i ate an under - cooked steamed fresh - water fish . i was not aware of the serious consequences about eating an under - cooked fresh - water fish . after that , i looked up on the internet and found that it can cause clonorchis sinensis , a kind of liver fluke . after reading the article talking about clonorchis in your website , i am so worried about being infected with clonorchis . do the chinese fresh - water fishes in united states contain this kind of liver fluke , or it only exists in area in asia ? also , where can i go to if i want to check for the parasite ?
egg of clonrochis sinensis . operculum , shoulder rim and surface wrinkling are distinctive . length of 28 - 30 micrometer , width 14 - 18 micrometer .
finally , changing agricultural practices that rely on human feces for fertilization of crops could help reduce infection with c . sinensis in some agricultural subsistence communities .
liver flukes include f hepatica , fasciola gigantica , c sinensis , opisthorchis felineus , o viverrini , dicrocoelium dendriticum , dicrocoelium hospes , and metorchis conjunctus .
clonorchis sinensis is a trematode in the phylum platyhelminthes [ 3 ] . because this parasite exhibits a three - host sequence , part of its life cycle takes place in aquatic habitats while the other part takes place in terrestrial habitats . the physical appearance of c . sinensis includes many forms : egg , miracidium , sporocyst , redia , cercaria , metacercaria , and adult [ 3 ] . c . sinensis is classified as hermaphroditic ; as a result , every single sexually mature form will produce eggs [ 3 ] . interestingly , each adult yields a daily production of 4000 eggs for at least six months [ 3 ] ! c . sinensis is currently infecting an estimated 30 , 000 , 000 humans and is believed to be the third most prevalent trematode parasite in the world [ 3 ] .
diagnosis is based on microscopic identification of eggs in stool specimens . however , the eggs of clonorchis are practically indistinguishable from those of opisthorchis . the adult fluke can also be recovered at surgery .
fish as a second intermediate host : in 1911 , japanese zoologist , harujiro kobayashi , found a fluke that was encysted in freshwater fish which inhabited the same regions where clonorchis infection was endemic . he fed cats , which had been suspected as a reservoir , the flesh of these infected fish and the cats all contracted c . sinensis . by 1965 , numerous fish species were found to be intermediate hosts for c . sinensis , although only a few species of fish were linked to human infections .
clonorchis sinensis is a liver fluke of human causing clonorchiasis , which is prevalent in east asia . clonorchiasis is now classified as one of food - borne nelgected tropical diseases . since cholangiocarcinoma is a serious complication , clonorchiasis is a major health concern in endemic areas [ 1 ] . as egg production is an important process for a fluke’s biology and detection of eggs is a base of diagnosis , several studies observed egg productivity of c . sinensis . it has been reported that c . sinensis produce about 4 , 000 eggs / worm / day in humans , 2 , 400 eggs / worm / day in cats , and 1 , 600 eggs / worm / day in guinea pigs [ 2 ] . however , it is still unknown that c . sinensis may produce their eggs by in vitro cultivation .
clonorchis sinensis requires two intermediate hosts for completion of its life cycle . the first is a snail and the second is cyprinoid fish ( although at least eight families of fish may serve as intermediate hosts for c . sinensis ) . among the snails , over 100 species in several general may serve as the primary intermediate host . in china , japan , korea , taiwan and other endemic areas , parafossarulus manchouricus is the most common snail host . other genera include bithynia , tarebia , alocinma and bulimus .
clonorchis is endemic in the far east , especially in korea , japan , taiwan , and southern china , and infection occurs elsewhere among immigrants and people eating raw or undercooked fish from endemic areas .
hong , s . t . , choi , m . h . , kim , c . h . , chung , b . s . , & ji , z . ( 2003 ) . the kato - katz method is reliable for diagnosis of clonorchis sinensis infection . diagnostic microbiology & infectious disease , 47 ( 1 ) , 345 - 347 .
wu w , qian x , huang y , hong q . a review of the control of clonorchiasis sinensis and taenia solium taeniasis / cysticercosis in china .
the eggs of clonorchis sinensis are taken in by snails that live in the freshwaters . these eggs hatch and the infected snails release microscopic larvae that enter freshwater fish ( a carp - like fish that serves as an intermediate host ) . humans ( or mammals ) , who are the final hosts , are infected when they eat raw or undercooked fish containing the cysts
xiao , s . h . , xue , j . , xu , l . l . , zheng , q . , qiang , h . q . , & zhang , y . n . ( 2009 ) . the in vitro and in vivo effect of tribendimidine and its metabolites against clonorchis sinensis . parasitology research , 105 ( 6 ) , 1497 - 1507 .
lee , s . h . , park , y . h . , sohn , w . m . , hong , s . t . , & chai , j . y . ( 1989 ) . the effects of gamma irradiation on the survival and development of clonorchis sinensis metacercariae . korean j parasitol , 27 ( 3 ) , 187 - 195 . retrieved from urltoken
the pathophysiology and clinical manifestations for o . viverrini and c . sinensis and infection are very similar ( lun et al . , 2005 ; sripa , 2008 ) .
in this context , the c . sinensis may act as a promoter in a two - stage carcinogenic process , which requires an initiator stimulus from an exogenous source .
clonorchis sinensis eggs are small , ranging in size from 27 to 35 µm by 11 to 20 µm . the eggs are oval shaped with a convex operculum , that rests on visible “shoulders” at the smaller end of the egg . at the opposite ( larger , abopercular ) end , a small knob or hooklike protrusion is often visible . the miracidium is visible inside the egg .
clonorchis sinensis is a zoonotic parasite causing clonorchiasis - associated human disease such as biliary calculi , cholecystitis , liver cirrhosis , and it is currently classified as carcinogenic to humans for cholangiocarcinoma . micrornas ( mirnas ) are non - coding , regulating small rna molecules which are essential for the complex life cycles of parasites and are involved in parasitic infections . to identify and characterize mirnas expressed in adult c . sinensis residing chronically in the biliary tract , we developed an integrative approach combining deep sequencing and bioinformatic predictions with stem - loop real - time pcr analysis .
the snail as the primary intermediate host : the japanese pathologist , masatomo muto , showed that the primary intermediate hosts of c . sinensis were snails . he infected natural , cyst - free fish by letting them incubate in the same tank with infected snails . these infected fish were then fed to uninfected dogs and guinea pigs . the ova of c . sinensis were subsequently found in the dogs and guinea pig feces a few weeks later ; at autopsy , adult c . sinensis were also observed in the biliary tract . muto correctly inferred that fish were a necessary stage in the development of c . sinensis because rabbits infected directly with cercariae from snails did not become infected .
n many places where c . sinensis is endemic , raw fish is a key ingredient in some local delicacies , so food preparation , as determined by cultural preference , becomes
xue - ming l , ying - dan c , yi o , hong - man z , rui l , weil m . overview of human clonorchiasis sinensis in china .
clonorchis is a liver fluke parasite ( trematode or worm ) that can infect the liver , gallbladder , and bile duct . found across parts of asia , it is also known as the chinese or oriental liver fluke .
in trematodes , vitelline precursor proteins are required for eggshell formation . a cdna clone of clonorchis sinensis ( csvpb1 ) was selected from an est pool , encoding a polypeptide of 245 amino acids . the csvpb1 polypeptide demonstrated homology with vitelline precursor proteins from trematodes with high sequential identities . in a phylogenic tree , csvpb1 clustered with trematode vpb proteins . the csvpb1 polypeptide was found to be rich in tyrosine residues , including putative predihydroxyphenyl alanine ( dopa ) residues , involved in cross - linking of the precursor proteins . mouse immune sera were raised against a recombinant csvpb1 protein . in adult c . sinensis , csvpb1 protein was exclusively localized in vitelline follicles . based on these results , the csvpb1 cdna is believed to encode a vpb of c . sinensis .
cirrhotic liver of a rabbit with chronic infection of clonrochis sinensis . liver margin discolored yellow and became fibrotic . several worms ( dark spots at the yellow part ) are seen .
some investigations ( 28 , 61 , 110 , 113 ) have reported synergism between liver fluke infection and exogenous chemical carcinogens with respect to cholangiocarcinoma development in hamsters . lee et al . ( 61 ) demonstrated a high incidence ( 75 % ) of cholangiocarcinoma in hamsters that were treated with n - nitrosodimethylamine and then infected with c . sinensis . they also observed that hamsters treated with n - nitrosodimethylamine prior to c . sinensis infection and hamsters exposed to n - nitrosodimethylamine and c . sinensis simultaneously developed cholangiocarcinoma in the liver whereas hamsters infected with c . sinensis prior to n - nitrosodimethylamine treatment and hamsters treated with either n - nitrosodimethylamine or c . sinensis , but not both , did not develop cholangiocarcinoma ( 62 ) . their results suggest that clonorchiasis in hamsters may have a promoting effect on cholangiocarcinoma development by inducing replication and fixing of n - nitrosodimethylamine - damaged dna before repair .
several trematode parasites in humans are known to be epidemiologically linked with malignancy ; notable examples are the associations between the blood - fluke schistosoma haematobium and tumors of the bladder urothelium ( 79 ) and between the liver - flukes clonorchis sinensis and opisthorchis viverrini and cholangiocarcinoma . the areas where human clonorchiasis , a disease caused by chronic c . sinensis infection , is endemic are confined largely to the far east . in these regions , clonorchiasis is considered an important cause of recurrent pyogenic cholangitis and cholangiocarcinoma . several well - documented epidemiological , histopathological , and experimental studies of c . sinensis have provided convincing evidence of a relationship between this trematode infection and the tendency for malignant transformation of the biliary epithelium in humans and experimentally infected animals ( 11 , 42 , 46 ) .
trematodes transmitted through fish are reviewed and species naturally infecting humans are listed . their medical importance , geographical distribution , and animal hosts are summarized . the most important group is liver flukes : amphimerus sp . , clonorchis sinensis , metorchis spp . , and opisthorchis spp . the others are clinostomes , echinostomes , heterophyids , and nanophyetids . the human infection amphimerus sp . can be found in ecuador ; and ascocotyle longa is a heterophyid that can be found in latin american countries . apophallus donicus , metorchis conjunctus , and nanophyetus salmincola can be found in north america ; opisthorchis felineus , metorchis bilis , and nanophyetus s . schikhobalowi exist in europe and northeast asia . the species that can be found in asia are clonorchis sinensis , metorchis orientalis , opisthorchis noverca , o . viverrini , clinostomes , echinostomes , and most heterophyids .
thirteen guinea pigs and 23 rabbits were challenged with 300 metacercariae of clonorchis sinensis each and the recovery of adult worms and egg counts in feces were compared at 11 - 13 weeks post - infection in guinea pigs and at 7 - 9 weeks post - infection in rabbits . the recovery rate of adult worm was 23 . 5 percent in guinea pigs and 20 . l - 30 . 5 percent in rabbits .
the c . sinensis genome was sequenced by the department of parasitology at zhongshan school of medicine , sun yat - sen university , as described by huang et al ( 2013 ) .
viet nam has been reported to be endemic for c . sinensis in the northern part , and o . viverrini in the southern region ( de et al . , 2003 ) .
to further elucidate the pathogenesis and carcinogenesis provoked by c . sinensis infection , comprehensive molecular and genetic information covering the different developmental stages of this parasite is required . in this study , we generated and sequenced transcriptome - scale ests from three developmental stages of c . sinensis and investigated the biological properties , growth , host adaptations , and pathogenic features of these different developmental stages .
liver fluke infection is endemic in china , japan , korea , taiwan , and vietnam ( c sinensis ) ; thailand and laos ( o viverrini ) ; and the russian federation and eastern europe ( o felineus ) . people who habitually eat raw or partially cooked fish or dried , salted , or pickled fish are more susceptible to infection by clonorchis species . c sinensis the most common liver fluke in east asia . its importance lies in the fact that it has been shown to be responsible for cholangiocarcinoma in humans . in 2009 , it was given the status of a group 1 biological carcinogen . [ 10 ]
several studies have provided evidence that o . viverrini ( 28 , 29 ) or c . sinensis infection ( 61 , 62 ) in hamsters acts as a promoter of the cholangiocarcinogenesis initiated by n - nitrosodimethylamine . more recently , cholangiocarcinogenesis by c . sinensis in hamsters was proposed as an experimental model to elucidate the role of oval cells in cholangiocarcinogenesis ( 35 , 61 ) . lee et al . ( 60 ) examined oval cells expressing different immunohistological phenotypes and ultrastructural appearances in hamsters during the cholangiocarcinogenesis induced by n - nitrosodimethylamine and c . sinensis infection . they concluded that activation ( initiation ) by n - nitrosodimethylamine and epithelial proliferation ( promotion ) by c . sinensis stimulate primitive oval cells or their progeny ( ductular - like oval cells ) to transform into cholangiocarcinomas .
positive diagnosis depends on identification of eggs from either feces or biliary drainage , and these must be differentiated from eggs of heterophyids ( see below ) . clinical examination is warranted whenever there is liver enlargement coupled with a history of residence in endemic areas . immunodiagnostic techniques using recombinant c . sinensis proteins as antigens for detecting c . sinensis - specific igg and ige antibodies are under investigation .