bluuebunny/crossref_metadata_2025 huggingface dataset:
Ecological fitness of Bacillus subtilis BGS3 regarding production of the surfactin lipopeptide in the rhizosphere
Authors: Nihorimbere Venant , Fickers Patrick , Thonart Philippe , Ongena Marc
Published: February 2009

Cyclic lipopeptides and particularly surfactins produced by Bacillus species retain antibacterial, antiviral, biofilm‐forming and plant resistance‐inducing activities. In most cases, their role in biological control of plant diseases was evoked on the basis of in vitro assays or by using non‐producing/overproducing mutants but there is a need for more direct evidence of an efficient lipopeptide biosynthesis in the rhizosphere. In this work, we coupled LC‐MS quantification of the lipopeptides secreted by cells colonizing tomato plants with the use of psrfA–lacZ reporter system integrated within the BGS3 chromosome to study the expression of the surfactin operon in planta. Results showed that a higher level of psrfA induction was observed upon the establishment of a stable BGS3 population on roots and surfactins extracted from the rhizosphere were produced in biologically significant quantities. Our results also demonstrate that BGS3 efficiently utilizes the main substrates from plant exudates to produce surfactins. This synthesis is also efficient in cells forming colonies and the production may be favoured in bacteria developing slowly in the rhizosphere. This provides a first understanding of how environmental factors may influence lipopeptide production by beneficial Bacillus strains.
South American native bumblebees (Hymenoptera: Apidae) infected by Nosema ceranae (Microsporidia), an emerging pathogen of honeybees (Apis mellifera)
Authors: Plischuk Santiago , Martín‐Hernández Raquel , Prieto Lourdes , Lucía Mariano , Botías Cristina , Meana Aránzazu , Abrahamovich Alberto H. , Lange Carlos , Higes Mariano
Published: February 2009

As pollination is a critical process in both human‐managed and natural terrestrial ecosystems, pollinators provide essential services to both nature and humans. Pollination is mainly due to the action of different insects, such as the bumblebee and the honeybee. These important ecological and economic roles have led to widespread concern over the recent decline in pollinator populations that has been detected in many regions of the world. While this decline has been attributed in some cases to changes in the use of agricultural land, the effects of parasites could play a significant role in the reduction of these populations. For the first time, we describe here the presence of Nosema ceranae, an emerging honeybee pathogen, in three species of Argentine native bumblebees. A total of 455 bumblebees belonging to six species of genus Bombus were examined. PCR results showed that three of the species are positive to N. ceranae (Bombus atratus, Bombus morio and Bombus bellicosus). We discuss the appearance of this pathogen in the context of the population decline of this pollinators.
Prevalence of Listeria spp Including Listeria monocytogenes from Apparently Healthy Sheep of Gujarat State, India
Authors: Yadav M. M. , Roy A.
Published: February 2009

A total of 1002 samples comprising blood (n = 248), faecal swabs (n = 248), nasal swabs (n = 248) and deep vaginal swabs (n = 248) collected from the 248 sheep and 10 environmental samples of 10 sheep flocks were examined for the presence of pathogenic Listeria spp. Confirmation of the isolates was based on biochemical tests followed by phenotypic characterization by haemolysis on sheep blood agar, Christie Atkins Munch‐Petersen (CAMP) test phosphatidylinositol‐specific phospholipase C (PI‐PLC) assay and phosphatidylcholine‐specific phospholipase C (PI‐PLC) assay. The isolates were subjected to genotypic characterization with the help of PCR assay for five virulence‐associated genes, plcA, prfA, hlyA, actA and iap. The L. monocytogenes isolates were further subjected for multiplex‐PCR‐based serotyping. From 1002 samples screened, 16 (1.60%) were found positive for Listeria spp. Of these, seven samples (0.7%) were confirmed as L. monocytogenes and nine (0.9%) as L. innocua. All the seven isolates of L. monocytogenes were haemolytic, CAMP‐positive, PI‐PLC‐positive, hlyA, pclA and prfA‐positive by PCR, while only four isolates turned out to be PC‐PLC‐positive (opaque zone surrounding the growth). All the seven isolates of L. monocytogenes were serotyped as 4b. In conclusion, the PI‐PLC assay and the virulence genes targeted PCR (plcA, prfA and hlyA plcA, prfA and actA genes for L. monocytogenes) hold a promise for rapid and reliable in vitro alternatives to in vivo pathogenicity tests.
Seroprevalence ofToxoplasma gondiiInfection in Stray and Household Cats in Guangzhou, China
Authors: Zhang H. , Zhou D. H. , Zhou P. , Lun Z. R. , Chen X. G. , Lin R. Q. , Yuan Z. G. , Zhu X. Q.
Published: February 2009

The prevalence of anti‐Toxoplasma gondiispecific IgG in stray and household cats in Guangzhou, China was determined by ELISA on serum samples from 206 cats (117 strays and 89 households) and the overall infection rate was 25.24%. The infection rate in stray cats (30.77%) was significantly higher (P < 0.05) than in household cats (17.98%). The rate of infection between male and female cats of both groups was not significantly different (P ≥ 0.05), 28.13% versus 32.61% for male and female in stray cats, respectively, and 18% versus 17.95% in household cats. The present investigation demonstrated that the prevalence ofT. gondiiinfection in cats in Guangzhou was high, especially in stray cats, which are probably the main source ofT. gondiiinfection in this area. Integrated control strategies and measures should be implemented to prevent and controlT. gondiiinfection in both stray and household cats, which will have significant implications for the control of human infection withT. gondii.
Faecal Sampling Underestimates the Actual Prevalence ofSalmonellain Laying Hen Flocks
Authors: Van Hoorebeke S. , Van Immerseel F. , De Vylder J. , Ducatelle R. , Haesebrouck F. , Pasmans F. , De Kruif A. , Dewulf J.
Published: February 2009

SummaryIn all European Union member states,Salmonellamonitoring in poultry flocks is obligatory. In these monitoring programmes, a limited number of pooled faeces and/or dust samples are collected to determine whetherSalmonellais present in the flocks or not. Whether these limited sampling protocols are sufficiently sensitive to detect expected low within‐flock prevalences of an intermittently shed pathogen is not yet clear. In this study, a comparison is made between different sampling procedures for the assessment of the between‐ and within‐flock prevalence ofSalmonellain laying hens. In total, 19 farms were sampled. Using a comparable sampling methodology as in the official surveillance programmes,Salmonellacould not be detected in any of the flocks. After transportation of the hens to the laboratory and subsequent analysis of cloacal swabs and caecal contents,SalmonellaEnteritidis was detected in laying hens from five of 19 farms. The observed within‐flock prevalence ranged from 1% to 14%. Based on the results of this study, it can be expected that, depending on the sampling procedure, different estimates of the prevalence ofSalmonellacan be obtained and the proportion ofSalmonellainfected flocks is underestimated based on the results of the official monitoring programme.
A Kinase-START Gene Confers Temperature-Dependent Resistance to Wheat Stripe Rust
Authors: Fu Daolin , Uauy Cristobal , Distelfeld Assaf , Blechl Ann , Epstein Lynn , Chen Xianming , Sela Hanan , Fahima Tzion , Dubcovsky Jorge
Published: February 2009

Stripe rust is a devastating fungal disease that afflicts wheat in many regions of the world. New races of
Puccinia striiformis
, the pathogen responsible for this disease, have overcome most of the known race-specific resistance genes. We report the map-based cloning of the gene
Yr36
(
WKS1
), which confers resistance to a broad spectrum of stripe rust races at relatively high temperatures (25° to 35°C). This gene includes a kinase and a putative START lipid-binding domain. Five independent mutations and transgenic complementation confirmed that both domains are necessary to confer resistance.
Yr36
is present in wild wheat but is absent in modern pasta and bread wheat varieties, and therefore it can now be used to improve resistance to stripe rust in a broad set of varieties.
A Putative ABC Transporter Confers Durable Resistance to Multiple Fungal Pathogens in Wheat
Authors: Krattinger Simon G. , Lagudah Evans S. , Spielmeyer Wolfgang , Singh Ravi P. , Huerta-Espino Julio , McFadden Helen , Bossolini Eligio , Selter Liselotte L. , Keller Beat
Published: February 2009

Agricultural crops benefit from resistance to pathogens that endures over years and generations of both pest and crop. Durable disease resistance, which may be partial or complete, can be controlled by several genes. Some of the most devastating fungal pathogens in wheat are leaf rust, stripe rust, and powdery mildew. The wheat gene
Lr34
has supported resistance to these pathogens for more than 50 years.
Lr34
is now shared by wheat cultivars around the world. Here, we show that the LR34 protein resembles adenosine triphosphate–binding cassette transporters of the pleiotropic drug resistance subfamily. Alleles of
Lr34
conferring resistance or susceptibility differ by three genetic polymorphisms. The
Lr34
gene, which functions in the adult plant, stimulates senescence-like processes in the flag leaf tips and edges.
Switchable Ferroelectric Diode and Photovoltaic Effect in BiFeO
3
Authors: Choi T. , Lee S. , Choi Y. J. , Kiryukhin V. , Cheong S.-W.
Published: February 2009

Unidirectional electric current flow, such as that found in a diode, is essential for modern electronics. It usually occurs at asymmetric interfaces such as p-n junctions or metal/semiconductor interfaces with Schottky barriers. We report on a diode effect associated with the direction of bulk electric polarization in BiFeO
3
: a ferroelectric with a small optical gap edge of ∼2.2 electron volts. We found that bulk electric conduction in ferroelectric monodomain BiFeO
3
crystals is highly nonlinear and unidirectional. This diode effect switches its direction when the electric polarization is flipped by an external voltage. A substantial visible-light photovoltaic effect is observed in BiFeO
3
diode structures. These results should improve understanding of charge conduction mechanisms in leaky ferroelectrics and advance the design of switchable devices combining ferroelectric, electronic, and optical functionalities.
Determinants of implementation of primary preventive interventions on patient handling in healthcare: a systematic review
Authors: Koppelaar E , Knibbe J J , Miedema H S , Burdorf A
Published: February 2009

Objective:

This systematic review aims (1) to identify barriers and facilitators during implementation of primary preventive interventions on patient handling in healthcare, and (2) to assess their influence on the effectiveness of these interventions.

Methods:

PubMed and Web of Science were searched from January 1988 to July 2007. Study inclusion criteria included evaluation of a primary preventive intervention on patient handling, quantitative assessment of the effect of the intervention on physical load or musculoskeletal disorders or sick leave, and information on barriers or facilitators in the implementation of the intervention. 19 studies were included, comprising engineering (n = 10), personal (n = 6) and multiple interventions (n = 3). Barriers and facilitators were classified into individual and environmental categories of factors that hampered or enhanced the appropriate implementation of the intervention.

Results:

16 individual and 45 environmental barriers and facilitators were identified. The most important environmental categories were “convenience and easy accessibility” (56%), “supportive management climate” (18%) and “patient-related factors” (11%). An important individual category was motivation (63%). None of the studies quantified their impact on effectiveness nor on compliance and adherence to the intervention.

Conclusion:

Various factors may influence the appropriate implementation of primary preventive interventions, but their impact on the effectiveness of the interventions was not evaluated. Since barriers in implementation are often acknowledged as the cause of the ineffectiveness of patient handling devices, there is a clear need to quantify the influence of these barriers on the effectiveness of primary preventive interventions in healthcare.
Molecular biogeographic study of recently described B- and A-genomeArachisspecies, also providing new insights into the origins of cultivated peanut
Authors: Burow Mark D. , Simpson Charles E. , Faries Michael W. , Starr James L. , Paterson Andrew H.
Published: February 2009

The cultivated peanut Arachis hypogaea is a tetraploid, likely derived from A- and B-genome species. Reproductive isolation of the cultigen has resulted in limited genetic variability for important traits. Artificial hybridizations using selected diploid parents have introduced alleles from wild species, but improved understanding of recently classified B-genome accessions would aid future introgression work. To this end, 154 cDNA probes were used to produce 1887 RFLP bands scored on 18 recently classified or potential B-genome accessions and 16 previously identified species. One group of B-genome species consisted of Arachis batizocoi , Arachis cruziana , Arachis krapovickasii , and one potential additional species; a second consisted of Arachis ipaënsis , Arachis magna , and Arachis gregoryi . Twelve uncharacterized accessions grouped with A-genome species. Many RFLP markers diagnostic of A. batizocoi group specificity mapped to linkage group pair 2/12, suggesting selection or genetic control of chromosome pairing. The combination of Arachis duranensis and A. ipaënsis most closely reconstituted the marker haplotype of A. hypogaea, but differences allow for other progenitors or genetic rearrangements after polyploidization. From 2 to 30 alleles per locus were present, demonstrating section Arachis wild species variation of potential use for expanding the cultigen’s genetic basis.
Genome size and nucleotypic variation inMalusgermplasm
Authors: Korban Schuyler S. , Wannarat Wannasiri , Rayburn Charlotte M. , Tatum Tatiana C. , Rayburn A. Lane
Published: February 2009

The genus Malus has anywhere between 25 and 33 species along with several subspecies. Malus species as well as clones within the same species have varying ploidy levels, as these are more than likely collected from different trees and (or) from different locations. In recent years, large numbers of Malus germplasm accessions have been collected and maintained at the United States National Germplasm Clonal Repository; however, genome sizes of this material have not yet been determined. In this study, leaf tissues from young grafted trees of 100 Malus species and hybrids growing in a nursery at the University of Illinois were collected and immediately used for extracting nuclei. Leaf tissues from apple and maize line W-22, used as an internal standard, were co-chopped and prepared for flow cytometric analysis. Apple nuclei were stained with propidium iodide, an intercalating dye, and a minimum of 8000 nuclei per sample were analyzed. Mean fluorescence of apple nuclei was then determined. A total of four replications per sample was used. Among 100 Malus accessions analyzed, one tetraploid, three triploid, and 96 diploid genotypes were identified. Significant differences in genome size were identified among the three ploidy types observed and also within diploid genotypes. The 2C mean value for tetraploids was 3.13 pg and ranged from 2.27 to 2.41 pg for triploids, whereas 2C values for diploids ranged between 1.44 and 1.72 pg. In addition, leaf impressions of young, fully expanded leaves were collected from young trees of 10 selected genotypes based on their ploidy and flow cytometric analysis and used to measure the nucleotypic parameter stomatal length. Ten stomata were measured per slide, three slides were analyzed per leaf, and three leaves were analyzed per accession. Overall, mean length of stomata ranged between 19.47 μm (diploid) and 27.6 μm (tetraploid), indicating that stomatal length in a tetraploid Malus genotype was 1.4-fold higher than that of a diploid genotype. A positive correlation between genome size and the nucleotypic parameter stomatal length was observed.
Two distinct major QTL for resistance to fire blight co-localize on linkage group 12 in apple genotypes ‘Evereste’ andMalus floribundaclone 821
Authors: Durel C.-E. , Denancé C. , Brisset M.-N.
Published: February 2009

Fire blight, caused by the bacterium Erwinia amylovora , is one of the most destructive diseases of apple (Malus ×domestica) worldwide. No major, qualitative gene for resistance to this disease has been identified so far in apple. A quantitative trait locus (QTL) analysis was performed in two F1progenies derived from two controled crosses: one between the susceptible rootstock cultivar ‘MM106’ and the resistant ornamental cultivar ‘Evereste’ and the other one between the moderately susceptible cultivar ‘Golden Delicious’ and the wild apple Malus floribunda clone 821, with unknown level of fire blight resistance. Both progenies were inoculated in the greenhouse with the same reference strain of E. amylovora. The length of stem necrosis was scored 7 and 14 days after inoculation. A strong QTL effect was identified in both ‘Evereste’ and M. floribunda 821 at a similar position on the distal region of linkage group 12 of the apple genome. From 50% to 70% of the phenotypic variation was explained by the QTL in ‘Evereste’ progeny according to the scored trait. More than 40% of the phenotypic variation was explained by the M. floribunda QTL in the second progeny. It was shown that ‘Evereste’ and M. floribunda 821 carried distinct QTL alleles at that genomic position. A small additional QTL was identified in ‘Evereste’ on linkage group 15, which explained about 6% of the phenotypic variation. Although it was not possible to confirm whether or not ‘Evereste’ and M. floribunda QTL belonged to the same locus or two distinct closely related loci, these QTL can be valuable targets in marker-assisted selection to obtain fire blight resistant apple cultivars and form a starting point for discovering the function of the genes controlling apple fire blight resistance.
Transformation of isolated barley (Hordeum vulgare L.) microspores: I. The influence of pretreatments and osmotic treatment on the time of DNA synthesis
Authors: Shim Youn-Seb , Pauls K. Peter , Kasha Ken J.
Published: February 2009

The objective of this study was to determine when DNA synthesis occurred during pretreatments of cultured barley ( Hordeum vulgare L.) microspores and during their preparation for particle bombardment. Based on this information, an investigation of the influence of cell cycle stage on the ability to obtain homozygous transgenic plants by particle bombardment will be presented in paper II of this series. It was hypothesized that the introduction of foreign genes at the G1 cell cycle stage in cultured uninucleate microspores would produce homozygous transgenic plants. Experiments were conducted with two different commonly used pretreatments to induce microspore embryogenesis: cold (4 °C) for 21days and cold plus 0.3 mol/L mannitol for 4 days. After pretreatment, the microspores were placed in a higher osmotic medium for 4 h prior to and for 18 h following bombardment. It was confirmed that during the cold plus mannitol pretreatment, there was no apparent change in the cell cycle stage, with the majority of the microspores remaining at the G1 stage. While in the cold for 21 days, the microspores progressed slowly through to G2, with a few progressing further into the mitosis and binucleate stages. Hourly DNA density measurements that were taken during the 4 h osmotic adjustment period following the cold plus mannitol pretreatment indicated that DNA synthesis began during this period at 25 °C, while at 4 °C, there was no apparent change in cell cycle stage or in DNA density. Thus, one might expect to find a higher frequency of homozygous doubled haploids by maintaining the temperature low during the 4 h osmotic adjustment period following the cold plus mannitol pretreatment than following the 21 day cold pretreatment. However, it is also not known what effect the temperatures during the whole high-osmotic treatments will have on the rate and time of incorporation of the transgene.
Transformation of isolated barley (Hordeum vulgareL.) microspores: II. Timing of pretreatment and temperatures relative to results of bombardment
Authors: Shim Youn-Seb , Pauls K. Peter , Kasha Ken J.
Published: February 2009

Based on paper I in this series, our goals in this paper were to determine the relationship between prebombardment pretreatments and temperatures, microspore cell cycle when bombarded, and the frequencies of homozygous and hemizygous transgenic progeny in barley ( Hordeum vulgare L.). Of the 104 fluorescent plants selected when using the GFP fluorescence transgene, 28 were albino and 76 plants were green. Thirty-one green plants were confirmed to be transgenic; the others were either transient green fluorescent protein expression or selected due to autofluorescence. Of the 31 plants, 23 came from embryos expressing a high level of fluorescence during selection and eight from 51 plants exhibiting a low level of fluorescence. Of the two pretreatments used to induce embryogenesis, 24 of 31 plants were from the cold pretreatment for 21 days (C) versus seven from the 4 day cold plus mannitol pretreatment. Following pretreatment, the microspores were subjected to a high-osmotic period (0.5 mol/L mannitol plus sorbitol) of 4 h prebombardment and 18 h postbombardment at either 25 or 4 °C. Of the 31 transgenic plants, 19 were produced following the 25 °C 4 h prebombardment. Sixteen of the 19 were doubled haploid plants (seven being homozygous for the transgene) and the other three plants were haploid. Of the remaining 12 plants recovered following the 4 h 4 °C prebombardment treatment, nine were haploid and three were doubled haploid plants, two of the latter being homozygous for the transgene. All 12 haploid plants obtained were treated with colchicine and produced homozygous transgenic doubled haploids. Of the two promoters compared, 30 plants had the actin promoter and only one had the 35S promoter. The use of arabinogalactan protein in the culture medium was very beneficial, giving rise to 29 of the 31 plants. The best procedure for obtaining transgenic barley plants from this study was pretreatment C, leaving the cultures at either 4 or 25 °C during the 4 h prebombardment high-osmotic period, using the actin promoter and having arabinogalactan protein in the microspore culture medium. With this procedure, the transgenic frequency was improved 8- to10-fold over previous reports on bombardment of microspores. It yielded about one transgenic plant per Petri dish and is comparable with Agrobacterium frequencies on structures derived from microspores.
Development of SCAR markers for sex determination in the dioecious shrub Aucuba japonica (Cornaceae)
Authors: Maki Masayuki
Published: February 2009

Two sex-linked fragments were identified by RAPD analyses in the dioecious diploid shrub Aucuba japonica var. ovoidea and were converted into markers of male-specific sequence characterized amplified region (SCAR) markers. PCRs using the primers designed in this study correctly discriminated 24 flowering males and 24 flowering females at higher annealing temperatures (SCAR markers OPA10-424 at 55 °C and OPN11-1095 at 65 °C), although at relatively low annealing temperatures, the fragments were amplified in both males and females. These SCAR primers were also tested to see whether they were applicable to sex identification in the conspecific tetraploid Aucuba japonica var. japonica. One set pf SCAR primers could be used for sex identification even in this tetraploid variety, although the other failed. The SCAR markers developed in this study will provide a powerful tool in identifying the sex of immature plants of dioecious A. japonica, which is a commercially valuable shrub due to its conspicuous fruits.
Delimitation of thePSH1(t) gene for rice purple leaf sheath to a 23.5 kb DNA fragment
Authors: Wang Wen-Ying , Ding Han-Feng , Li Guang-Xian , Jiang Ming-Song , Li Run-Fang , Liu Xu , Zhang Yu , Yao Fang-Yin
Published: February 2009

Leaf sheath color plays an important role as a marker for rice genetic improvement. A recombinant inbred line (RIL) population consisting of 220 individuals was developed from a cross between an Oryza sativa subsp. indica variety, IRBB60, and an Oryza sativa subsp. japonica variery, 9407. Within the RIL population, a line, RI51, was found to have purple leaf sheath (PSH). To map the gene governing PSH, RI51 was crossed with 9407 green leaf sheath (GSH) to develop an F2segregating population. The distribution of F2plants with PSH and GSH fitted a segregation ratio of 3:1, indicating that the PSH was controlled by a major dominant gene. The gene locus for PSH, tentatively designated as PSH1(t), was identified by surveying two bulks made of the respective 40 individuals with PSH and GSH with SSR markers covering the entire rice genome. The survey indicated that the PSH1(t) region was located on chromosome 1. Further confirmation was made using a large random sample of 360 individuals from the same F2population and the PSH1(t) locus was then mapped on chromosome 1 between SSR markers RM3475 and RM7202 with genetic distances of 2.0 and 1.1 cM, respectively. For fine mapping of PSH1(t), a large F2:3segregating population with 3300 individuals from the seven heterozygous F2plants in the RM3475–RM7202 region was constructed. Analysis of recombinants in the PSH1(t) region anchored the gene locus to an interval of 23.5 kb flanked by the left marker L03 and the right marker L05. Sequence analysis of this fragment predicted six open reading frames encoding a putative trans-sialidase, a putative Plastidic ATP/ADP-transporter, and four unknown proteins. The detailed genetic and physical maps of the PSH1(t) locus will be very useful in molecular cloning of the PSH1(t) gene.
Construction of chromosomal recombination maps of three genomes of lilies (Lilium) based on GISH analysis
Authors: Khan Nadeem , Barba-Gonzalez Rodrigo , Ramanna M. S. , Visser Richard G.F. , Van Tuyl Jaap M.
Published: February 2009

Chromosomal recombination maps were constructed for three genomes of lily ( Lilium ) using GISH analyses. For this purpose, the backcross (BC) progenies of two diploid (2n = 2x = 24) interspecific hybrids of lily, viz. Longiflorum × Asiatic (LA) and Oriental × Asiatic (OA), were used. Mostly the BC progenies of LA hybrids consisted of both triploid (2n = 3x = 36) and diploid (2n = 2x = 24) with some aneuploid genotypes and those of OA hybrids consisted of triploid (2n = 3x = 36) and some aneuploid genotypes. In all cases, it was possible to identify the homoeologous recombinant chromosomes as well as accurately count the number of crossover points, which are called “recombination sites”. Recombination sites were estimated in the BC progeny of 71 LA and 41 OA genotypes. In the case of BC progenies of LA hybrids, 248 recombination sites were cytologically localized on 12 different chromosomes of each genome (i.e., L and A). Similarly, 116 recombinant sites were localized on the 12 chromosomes each from the BC progenies of OA hybrids (O and A genomes). Cytological maps were constructed on the basis of the percentages of distances (micrometres) of the recombination sites from the centromeres. Since an Asiatic parent was involved in both hybrids, viz. LA and OA, two maps were constructed for the A genome that were indicated as Asiatic (L) and Asiatic (O). The other two maps were Longiflorum (A) and Oriental (A). Remarkably, the recombination sites were highly unevenly distributed among the different chromosomes of all four maps. Because the recombination sites can be unequivocally identified through GISH, they serve as reliable landmarks and pave the way for assigning molecular markers or desirable genes to chromosomes of Lilium and also monitor introgression of alien segments.
Genome size is inversely correlated with relative brain size in parrots and cockatoos
Authors: Andrews Chandler B. , Gregory T. Ryan
Published: February 2009

Genome size (haploid nuclear DNA content) has been found to correlate positively with cell size and negatively with cell division rate in a variety of taxa. These cytological relationships manifest in various ways at the organism level, for example, in terms of body size, metabolic rate, or developmental rate, depending on the biology of the organisms. In birds, it has been suggested that high metabolic rate and strong flight ability are linked to small genome size. However, it was also hypothesized that the exceptional cognitive abilities of birds may impose additional constraints on genome size through effects on neuron size and differentiation, as has been observed in amphibians. To test this hypothesis, a comparative analysis was made between genome size, cell (erythrocyte) size, and brain size in 54 species of parrots and cockatoos (order Psittaciformes, family Psittacidae). Relative brain volume, which is taken as an indicator of investment in brain tissue and is widely correlated with behavioural and ecological traits, was found to correlate inversely with genome size. Several possible and mutually compatible explanations for this relationship are described.
Genome size in natural and synthetic autopolyploids and in a natural segmental allopolyploid of several Triticeae species
Authors: Eilam T. , Anikster Y. , Millet E. , Manisterski J. , Feldman M.
Published: February 2009

Nuclear DNA amount (1C) was determined by flow cytometry in the autotetraploid cytotype of Hordeum bulbosum , in the cytologically diploidized autotetraploid cytotypes of Elymus elongatus , Hordeum murinum subsp. murinum and Hordeum murinum subsp. leporinum, in Hordeum marinum subsp. gussoneanum, in their progenitor diploid cytotypes, and in a newly synthesized autotetraploid line of E. elongatus. Several lines collected from different regions of the distribution area of every taxon, each represented by a number of plants, were analyzed in each taxon. The intracytotype variation in nuclear DNA amount of every diploid and autotetraploid cytotype was very small, indicating that no significant changes have occurred in DNA amount either after speciation or after autopolyploid formation. The autotetraploid cytotypes of H. bulbosum and the cytologically diploidized H. marinum subsp. gussoneanum had the expected additive amount of their diploid cytotypes. On the other hand, the cytologically diploidized autotetraploid cytotypes of E. elongatus and H. murinum subsp. murinum and H. murinum subsp. leporinum had considerably less nuclear DNA (10%–23%) than the expected additive value. Also, the newly synthesized autotetraploid line of E. elongatus showed similar reduction in DNA as its natural counterpart, indicating that the reduction in genome size occurred in the natural cytotype during autopolyploidization. It is suggested that the diploid-like meiotic behavior of these cytologically dipolidized autotetraploids is caused by the instantaneous elimination of a large number of DNA sequences, different sequences from different homologous pairs, leading to differentiation of the constituent genomes. The eliminated sequences are likely to include those that participate in homologous recognition and initiation of meiotic pairing. A gene system determining exclusive bivalent pairing by utilizing the differentiation between the two groups of homologues has been presumably superimposed on the DNA reduction process.
Characterization of a tandemly repeated subtelomeric sequence with inverted telomere repeats in maize
Authors: Li Jun , Yang Fei , Zhu Jia , He Shibin , Li Lijia
Published: February 2009

In this study, two complementary telomere primers were applied to a single-primer PCR. A clear amplification band was obtained with one primer, while a smear pattern was seen with the other primer. Sequence analysis of the isolated clones from this specific amplification band revealed that a 412 bp clone designated as MTAS1 shared high homology with a reported subtelomeric sequence (382 bp) from maize ( Zea mays L.), which indicated that this clone was possibly present at subtelomeric regions. The clone MTAS1 displayed a novel structural feature flanked by the forward and inverted telomere repeats. Southern hybridization revealed a ladder of hybridization bands, suggesting that MTAS1 was a tandemly repeated sequence. Fluorescence in situ hybridization results showed that the strong MTAS1 signals were present at the ends of short arms of several long chromosomes, confirming that MTAS1 was a subtelomeric sequence and the high brightness of signals further indicated this cloned sequence was a highly and tandemly repetitive sequence in maize. Fluorescence in situ hybridization with telomeric DNA and MTAS1 as probes on metaphase chromosomes and extended genomic DNA fibers showed that hybridization signals of this clone located adjacent to or overlapped with signals of telomere tandem repeats distributed heterogeneously in subtelomeric regions of several chromosomes and even exhibited differences in two subtelomeres of a single chromosome.
An acute bout of endurance exercise but not sprint interval exercise enhances insulin sensitivity
Authors: Brestoff Jonathan R. , Clippinger Benjamin , Spinella Thomas , von Duvillard Serge P. , Nindl Bradley , Arciero Paul J.
Published: February 2009

An acute bout of endurance exercise (EE) enhances insulin sensitivity, but the effects of sprint interval exercise (SIE) have not yet been described. We sought to compare insulin sensitivity at baseline and after an acute bout of EE and SIE in healthy men (n = 8) and women (n = 5) (age, 20.7 ± 0.3 years; peak oxygen consumption (VO2 peak), 42.6 ± 1.7 mL·kg–1·min–1; <1.5 days·week–1 structured exercise; body fat, 21.1 ± 1.9%). Subjects underwent 3 oral glucose tolerance tests (OGTTs) the day after each of the following 3 conditions: no exercise, baseline (OGTTB); SIE at ~125% VO2 peak (OGTTSIE); and EE at ~75% VO2 peak (OGTTEE). SIE and EE sessions were randomized for each subject. Subjects consumed identical meals the day preceding each OGTT. Two insulin sensitivity indices — composite whole-body insulin sensitivity index (ISI-COMP) and ISI-hepatic insulin sensitivity (HOMA) — were calculated, using previously validated formulas (ISI-COMP = 10 000/√(glucosefasting × insulinfasting × glucosemean OGTT × insulinmean OGTT); ISI-HOMA = 22.5/(insulinfasting × glucosefasting)), and the plasma concentrations of cytokines interleukin-6 and tumor necrosis factor-α were measured. There were no differences by sex for any condition (men vs. women, p > 0.05). Pearson’s correlation coefficients between ISI-COMP and ISI-HOMA for each condition were highly correlated (p < 0.01), and followed similar patterns of response. ISI-COMPEE was 71.4% higher than ISI-COMPB (8.4 ± 1.4 vs. 4.9 ± 1.0; p < 0.01) and 40.0% higher than ISI-COMPSIE (8.4 ± 1.4 vs. 6.0 ± 1.5; p < 0.05), but there was no difference between ISI-COMPB and ISI-COMPSIE (p = 0.182). VO2 peak was highly correlated with both ISI-COMP and ISI-HOMA during baseline and SIE test conditions (p < 0.02). These findings demonstrate that an acute bout of EE, but not SIE, increases insulin sensitivity relative to a no-exercise control condition in healthy males and females. While these findings underscore the use of regular EE as an effective intervention strategy against insulin resistance, additional research examining repeated sessions of SIE on insulin sensitivity is warranted.
Using simple anthropometric measures to predict body fat in South Asians
Authors: Kohli Simi , Gao Min , Lear Scott A.
Published: February 2009

Previously determined predictive equations for body fat mass (BFM) are primarily derived from populations of European origin, which may not be appropriate for all ethnic groups. The objective of this study was to develop an improved predictive equation for BFM specific to South Asians and derived from common anthropometric measurements that include measures of central adiposity. A total of 208 apparently healthy South Asian men and women, aged 30–65 years, were recruited. Anthropometric measurements and BFM by dual energy X-ray absorbitometry (DEXA) were obtained. Sex-specific equations predicting BFM were developed using regression models on a reference subset (68 men, 70 women) and tested on a validation group. New predictive equations (BFMNEW) were tested for agreement with Durin and Wormersley and Siri equations and with the reference method, DEXA. The best predictive sex-specific equation involved a combination of skinfolds, waist circumference, hip circumference, humerus breadth, height, mass, and age. Models significantly correlated with BFM determined by DEXA (r = 0.946 for men; r = 0.974 for women; p < 0.001). The estimates of BFM from reference and validation groups had excellent correlations and displayed excellent agreement to DEXA measures. We demonstrated new predictive equations for BFM that are specific to South Asians and incorporate measures of central adiposity. This may help resolve issues surrounding inaccurate determination of adiposity in South Asians, and consequently provide better estimations of disease risk.
Effect of different models of physical exercise on oxidative stress markers in mouse liver
Authors: da Silva Luciano A. , Pinho Cleber A. , Rocha Luis G.C. , Tuon Talita , Silveira Paulo C.L. , Pinho Ricardo A.
Published: February 2009

The aim of this study was to investigate the effect of different protocols of physical exercise on oxidative stress markers in mouse liver. Twenty-eight male CF1 mice (30–35 g) were distributed into 4 groups (n = 7) — untrained (UT), continuous running (CR), downhill running (D-HR), and intermittent running (IR) — and underwent an 8-week training program. Forty-eight hours after the last training session, the animals were killed, and their livers were removed. Blood lactate, creatine kinase, citrate synthase, thiobarbituric acid reactive species, carbonyl, superoxide dismutase (SOD), and catalase (CAT) activities were assayed. Results show a decrease in the level of lipoperoxidation and protein carbonylation in the CR and D-HR groups. SOD activity was significantly increased and CAT activity was reduced in the CR and D-HR groups. Our findings indicate that CR and D-HR may be important for decreasing oxidative damage and in the regulation of antioxidant enzymes (SOD and CAT) in the livers of trained mice.
Alpha-linolenic acid supplementation and resistance training in older adults
Authors: Cornish Stephen M. , Chilibeck Philip D.
Published: February 2009

Increased inflammation with aging has been linked to sarcopenia. The purpose of this study was to evaluate the effects of supplementing older adults with alpha-linolenic acid (ALA) during a resistance training program, based on the hypothesis that ALA decreases the plasma concentration of the inflammatory cytokine tumor necrosis factor (TNF)-α and interleukin (IL)-6, which in turn would improve muscle size and strength. Fifty-one older adults (65.4 ± 0.8 years) were randomized to receive ALA in flax oil (~14 g·day–1) or placebo for 12 weeks while completing a resistance training program (3 days a week). Subjects were evaluated at baseline and after 12 weeks for muscle thickness of knee and elbow flexors and extensors (B-mode ultrasound), muscle strength (1 repetition maximum), body composition (dual energy X-ray absorptiometry), and concentrations of TNF-α and IL-6. Males supplementing with ALA decreased IL-6 concentration over the 12 weeks (62 ± 36% decrease; p = 0.003), with no other changes in inflammatory cytokines. Chest and leg press strength, lean tissue mass, muscle thickness, hip bone mineral content and density, and total bone mineral content significantly increased, and percent fat and total body mass decreased with training (p < 0.05), with the only benefit of ALA being a significantly greater increase in knee flexor muscle thickness in males (p < 0.05). Total-body bone mineral density improved in the placebo group, with no change in the ALA group (p = 0.05). ALA supplementation lowers the IL-6 concentration in older men but not women, but had minimal effect on muscle mass and strength during resistance training.
Improved endurance capacity following chocolate milk consumption compared with 2 commercially available sport drinks
Authors: Thomas Kevin , Morris Penelope , Stevenson Emma
Published: February 2009

This study examined the effects of 3 recovery drinks on endurance performance following glycogen-depleting exercise. Nine trained male cyclists performed 3 experimental trials, in a randomized counter-balanced order, consisting of a glycogen-depleting trial, a 4-h recovery period, and a cycle to exhaustion at 70% power at maximal oxygen uptake. At 0 and 2 h into the recovery period, participants consumed chocolate milk (CM), a carbohydrate replacement drink (CR), or a fluid replacement drink (FR). Participants cycled 51% and 43% longer after ingesting CM (32 ± 11 min) than after ingesting CR (21 ± 8 min) or FR (23 ± 8 min). CM is an effective recovery aid after prolonged endurance exercise for subsequent exercise at low-moderate intensities.
Prefrontal cortex oxygenation is preserved and does not contribute to impaired neuromuscular activation during passive hyperthermia
Authors: Morrison Shawnda A. , Sleivert Gordon G. , Neary J. Patrick , Cheung Stephen S.
Published: February 2009

We investigated the role of passive hyperthermia upon motor unit activation and prefrontal cortex oxygenation. Six healthy males were passively heated, using a liquid conditioning garment in a hot environment (35 °C, 50% relative humidity). Maximal force output and voluntary activation were examined during a 10 s maximal isometric knee extension. Of the initial 6 subjects, 1 experienced syncope at a rectal temperature (Tre) of 38.0 °C and was removed from the study. The remaining 5 subjects completed heating and testing to a Tre of 38.5 °C (n = 1), 39.0 °C (n = 3), or 39.5 °C (n = 1), and then were cooled back to baseline. Force production decreased from 553 ± 133 to 430 ± 176 N (p < 0.01) with passive heating, as did voluntary activation (from 90 ± 5% to 84 ± 7%). Percent heart rate reserve increased from 8 ± 5% to 59 ± 3% before returning to 4 ± 8% (p < 0.001). Although mean arterial pressure remained unchanged, there were significant decreases in diastolic blood pressure with heating (80 ± 3 to 63 ± 8 mm Hg). Passive heating did not alter prefrontal cortex oxygenation, but cooling back to baseline core temperature attenuated cerebral oxygenated and total hemoglobin levels (p < 0.05). Passive heating to the point of voluntary exhaustion elevated cardiovascular and thermal strain and subjective perceptions of thermal discomfort. However, while this resulted in a marked decrement in maximal isometric force production and central voluntary activation, no concomitant changes in cerebral oxygenation were observed, suggesting that overall cerebrovascular regulation was maintained.
The dynamics of HMG protein–chromatin interactions in living cellsThis paper is one of a selection of papers published in this Special Issue, entitled CSBMCB’s 51st Annual Meeting – Epigenetics and Chromatin Dynamics, and has undergone the Journal’s usual peer review process.
Authors: Gerlitz Gabi , Hock Robert , Ueda Tetsuya , Bustin Michael
Published: February 2009

The dynamic interaction between nuclear proteins and chromatin leads to the functional plasticity necessary to mount adequate responses to regulatory signals. Here, we review the factors regulating the chromatin interactions of the high mobility group proteins (HMGs), an abundant and ubiquitous superfamily of chromatin-binding proteins in living cells. HMGs are highly mobile and interact with the chromatin fiber in a highly dynamic fashion, as part of a protein network. The major factors that affect the binding of HMGs to chromatin are operative at the level of the single nucleosome. These factors include structural features of the HMGs, competition with other chromatin-binding proteins for nucleosome binding sites, complex formation with protein partners, and post-translational modifications in the protein or in the chromatin-binding sites. The versatile modulation of the interaction between HMG proteins and chromatin plays a role in processes that establish the cellular phenotype.
YEATS domain proteins: a diverse family with many links to chromatin modification and transcriptionThis paper is one of a selection of papers published in this Special Issue, entitled CSBMCB’s 51st Annual Meeting – Epigenetics and Chromatin Dynamics, and has undergone the Journal’s usual peer review process.
Authors: Schulze Julia M. , Wang Alice Y. , Kobor Michael S.
Published: February 2009

Chromatin modifications play crucial roles in various biological processes. An increasing number of conserved protein domains, often found in multisubunit protein complexes, are involved in establishing and recognizing different chromatin modifications. The YEATS domain is one of these domains, and its role in chromatin modifications and transcription is just beginning to be appreciated. The YEATS domain family of proteins, conserved from yeast to human, contains over 100 members in more than 70 eukaryotic species. Yaf9, Taf14, and Sas5 are the only YEATS domain proteins in Saccharomyces cerevisiae. Human YEATS domain family members, such as GAS41, ENL, and AF9, have a strong link to cancer. GAS41 is amplified in glioblastomas and astrocytomas; ENL and AF9 are among the most frequent translocation partners of the mixed lineage leukemia (MLL) gene. This review will focus on the best characterized YEATS proteins, discuss their diverse roles, and reflect potential functions of the YEATS domain.
YAP, TAZ, and Yorkie: a conserved family of signal-responsive transcriptional coregulators in animal development and human diseaseThis paper is one of a selection of papers published in this Special Issue, entitled CSBMCB’s 51st Annual Meeting – Epigenetics and Chromatin Dynamics, and has undergone the Journal’s usual peer review process.
Authors: Wang Kainan , Degerny Cindy , Xu Minghong , Yang Xiang-Jiao
Published: February 2009

How extracellular cues are transduced to the nucleus is a fundamental issue in biology. The paralogous WW-domain proteins YAP (Yes-associated protein) and TAZ (transcriptional coactivator with PDZ-binding motif; also known as WWTR1, for WW-domain containing transcription regulator 1) constitute a pair of transducers linking cytoplasmic signaling events to transcriptional regulation in the nucleus. A cascade composed of mammalian Ste20-like (MST) and large tumor suppressor (LATS) kinases directs multisite phosphorylation, promotes 14-3-3 binding, and hinders nuclear import of YAP and TAZ, thereby inhibiting their transcriptional coactivator and growth-promoting activities. A similar cascade regulates the trafficking and function of Yorkie, the fly orthologue of YAP. Mammalian YAP and TAZ are expressed in various tissues and serve as coregulators for transcriptional enhancer factors (TEFs; also referred to as TEADs, for TEA-domain proteins), runt-domain transcription factors (Runxs), peroxisome proliferator-activated receptor γ (PPARγ), T-box transcription factor 5 (Tbx5), and several others. YAP and TAZ play distinct roles during mouse development. Both, and their upstream regulators, are intimately linked to tumorigenesis and other pathogenic processes. Here, we review studies on this family of signal-responsive transcriptional coregulators and emphasize how relative sequence conservation predicates their function and regulation, to provide a conceptual framework for organizing available information and seeking new knowledge about these signal transducers.