bluuebunny/crossref_metadata_2025 huggingface dataset:
Evolution in the Murinae (Rodentia) Assessed by Microcomplement Fixation of Albumin
Authors: Watts CHS , Baverstock PR
Published: June 2005

The inter-relationship of 17 genera of Murinae rodents were studied using microcomplement fixation of albumin to measure immunological distances among taxa. The genera chosen represented six major clades and four monogeneric groups identified in earlier companion studies (an African group, a South-east Asian group, a New Guinean group, an Australasian group, an Acomys group, a Micromys group and Apodemus, Millardia, Mus and Phloeomys). When these companion studies are included 136 species and 67 genera were studied. Ten major clades were consistently supported by the data but apart from linking the South-east Asian and Australasian clades, the data do not resolve their inter-relationships. The Acomys-Uranomys-Lophouromys clade may be the sister-group to the rest of the Murinae. Otomys (Otomyinae) is considered to be a murine related to the African group of genera. Of the ten major clades identified, only one (Mus) occurs significantly in more than one primary biogeographic region. It is suggested that following an early period of relatively rapid dispersal from the place of origin, little further dispersal took place and subsequent evolution occurred within relatively confined geographic areas.
The Kidney Structure of the Common Wombat (Vombatus-Ursinus) and the Hairy-Nosed Wombat (Lasiorhinus-Latifrons)
Authors: Mcallan BM , Roberts JR , Barboza PS
Published: June 2005

The common wombat (Vombatus ursinus) lives in a mesic habitat whereas the hairy-nosed wombat (Lasiorhinus latifrons) inhabits a xeric habitat. The kidney structure of these two wombats was studied and it was found that kidney size, kidney weight, and kidney weight as a percentage of body weight, were larger in V. ursinus. However, relative medullary thickness, percentage medullary volume, and medullary thickness as a percentage of total thickness, were significantly greater in L. latifrons, suggesting that L. latifrons has a greater capacity to conserve water than does V. ursinus. The number of glomeruli and mean glomerular area were the same in both species whereas the mean diameter of the proximal and distal tubules was larger in V. ursinus. There were more proximal tubules per square millimetre in L. latifrons. The larger number of collecting ducts per square millimetre in the medullary region in L. latifrons indicates that the nephrons join the collecting ducts deep in the medulla, a feature that has been associated with increased urinary concentrating ability. Urinary pH was significantly lower, and urinary ammonia, creatinine and sodium levels were higher, in L. latifrons, as were plasma sodium and chloride levels. These data suggest that L. latifrons has a greater capacity to conserve water.
Relationship Between Survival Rate and Survival-Time of Rabbits, Oryctolagus-Cuniculus (L), Challenged With Myxoma Virus
Authors: Parer I
Published: June 2005

The mean survival times of small groups of rabbits challenged with myxoma virus have been used to estimate survival rates and to allocate virulence grades to field strains of myxoma virus. The slope of the regression Line relating survival percentage to mean survival time in days was shown to be less steep than has been previously estimated. This overestimation of the regression slope has, in the past, resulted in most field strains of myxoma virus being allocated to the Grade III level of virulence when allocation to Grade I would have been more appropriate.
The Mating System of Free-Living Emus
Authors: Coddington CL , Cockburn A
Published: June 2005

Despite their pivotal role in interpretation of the complex mating systems of the ratites, the mating system of free-living emus (Dromaius novaehollandiae) has not been characterised. Here we report observations on an introduced but free-ranging population of emus at Tidbinbilla Nature Reserve in the Australian Capital Territory. Emus combined monogamy, polyandry and promiscuity. All initially unpaired males paired with and incubated a clutch for females whose primary mates were preoccupied with incubation. However, females were also promiscuous, and most copulations we observed were extra-pair. Females fight vigorously among themselves for access to unpaired males. Coupled with observations on cassowaries, these data suggest that there is no simple correlation between habitat (grassland/forest) and the mating system in ratites. Instead, the resolution of the complex conflicts of interest between the sexes appears to determine the predominant mating systems exhibited by a species.
Hibernation in Free-Living Mountain Pygmy-Possums, Burramys Parvus (Marsupialia, Burramyidae)
Authors: Broome LS , Geiser F
Published: June 2005

The long-term pattern of hibernation was studied in free-living mountain pygmy-possums, Burramys parvus, using temperature-sensitive radio-collars. Most males and females began to hibernate in early June within one week of their release. Hibernation was interrupted by spontaneous arousals that were followed by short normothermic periods and re-entry into torpor. The duration of multiday torpor bouts averaged 8 . 0 days (range 3-17 days) and arousal periods averaged 19 . 1 h. Single-day torpor bouts were observed occasionally. The duration of torpor bouts lengthened with the progress of the hibernation season and normothermic periods became shorter. The pattern of hibernation in free-living B. parvus was similar to that of captive individuals maintained under temperature regimes that were similar to those in the wild.
Population-Growth Potential of Epiphyas-Postvittana, the Lightbrown Apple Moth (Lepidoptera, Tortricidae) in Relation to Diet, Temperature and Climate
Authors: Danthanarayana W , Gu H , Ashley S
Published: June 2005

Life-history parameters and developmental rates of Epiphyas postvittana were determined for four natural food plants and Shorey's diet at each of six temperatures. The rate of development of larvae and the life-history parameters were influenced by both temperature and diet. The highest r(m) value was given by populations feeding on Plantago lanceolata, followed by those on Shorey's diet and Rumex crispus, all at 25 . 2 degrees C, then by Malus pumila at 19 . 9 degrees C and Trifolium repense at 25 . 2 degrees C. Zero population growth occurred at 7 . 1 and 30 . 7 degrees C. A life-table study of five geographical strains of the moth under non-variable conditions (constant temperature and artificial diet) showed that finite rate of increase (lambda) was significantly correlated with climatic features of habitats, viz. mean annual Values of temperature, rainfall and relative humidity. Peak values of lambda occurred at cooler temperatures, moderate levels of habitat moisture and high altitudes (500-1000 m); the Canberra population gave the highest value (lambda = 1 . 157), followed by Armidale (lambda = 1 . 152), Melbourne (lambda = 1 . 141), Mildura (lambda = 1 . 135) and Auckland (lambda = 1 . 118). Higher performance of E. postvittana on herbaceous plants than on woody plants suggests that it primarily evolved as a feeder on herbaceous plants.
Phylogeny of the Pteropodidae (Mammalia, Chiroptera) Based on Dna Hybridization, With Evidence for Bat Monophyly
Authors: Kirsch JAW , Flannery TF , Springer MS , Lapointe FJ
Published: June 2005

We constructed DNA-hybridisation matrices comparing 18 genera of Megachiroptera and an outgroup microchiropteran, and eight species of Pteropus and two related genera. Three species each of Megachiroptera and Microchiroptera, two of Primates, and an outgroup armadillo were compared in another matrix; additional representatives of other mammalian orders figured in a further set of experiments. Among the megachiropterans examined, Nyctimene and Paranyctimene comprise the sister-group to other pteropodids. Of the 'macroglossines', only Macroglossus and Syconycteris are associated apart from typical pteropodines, while the four remaining nectar-feeders (Eonycteris, Megaloglossus, Melonycteris, Notopteris) are independently linked with non-nectar-feeding clades. Thus, Megaloglossus is the nearest relative of Lissonycteris, with Epomophorus and Rousettus successive sister-groups to both, while Eonycteris is the sister of all four; Melonycteris and Pteralopex form a trichotomy with the closely related Acerodon and Pteropus, and Notopteris is the sister-taxon to all four. It therefore appears that anatomical specialisations for nectar- and pollen-feeding evolved (or were lost) several times within Pteropodidae. Cynopterus and Dobsonia represent additional clades within the Pteropodinae, with which Thoopterus and Aproteles are respectively paired. Comparisons among species of Pteropus and related genera suggest that Acerodon may be congeneric with Pteropus, but that Pteralopex clearly is not. The ordinal-level matrices support bat monophyly: no order tested is closer to either of the chiropteran suborders than they are to each other, and bats are separated from Primates by at least two nodes. On the basis of previous rate determinations for mammals, we estimate that the African grouping (Epomophorus, Megaloglossus, Lissonycteris) is mid-Miocene in origin, that the two major pteropodid subfamilies (Nyctimeninae and Pteropodinae, including 'Macroglossinae') separated in the Early Miocene, and that the divergence of chiropteran suborders dates from the latest Cretaceous or earliest Palaeocene. Arrangement of genera within Pteropodidae supports the family's Australo-Pacific or south-east Asian origin.
Female-Specific Restriction Fragments Revealed by Dna-Fingerprinting and Implications for Extra-Pair Fertilisations in the Short-Tailed Shearwater (Puffinus-Tenuirostris, Procellariiformes, Procellariidae)
Authors: Austin JJ , Parkin DT
Published: June 2005

We report a female-specific restriction fragment in the DNA fingerprints of short-tailed shearwaters (Puffinus tenuirostris) that hybridises to a derivative of the human multilocus minisatellite probe 33.6. This genetic method of assigning sex has relevance to studies of population biology, reproductive success and mating systems in this species. The presence or absence of the female-specific restriction fragment has allowed us to reinterpret results from a previous DNA fingerprinting study of mating systems in the short-tailed shearwater.
Primary Parasitism, Development and Adult Biology in the Wasp Taeniogonalos Venatoria Riek (Hymenoptera: Trigonalyidae)
Authors: Weinstein P , Austin AD
Published: June 2005

The biology of the Australian wasp Taeniogonalos venatoria Riek was investigated using populations in the Adelaide Region during 1986-90. This species is unusual for a trigonalyid because it is a primary parasitoid of a pergid sawfly and can act facultatively as a hyperparasitoid. The wasp oviposits onto foliage, eggs are ingested by host larvae, eggs then hatch, and the larva penetrates the gut wall. Saline, acid saline, cathepsin and physical manipulation were effective in triggering eclosion. Eggs were viable on foliage for up to 5 months. Larval instars 1-3 are endoparasitic; 4-5 are ectoparasitic. Populations are univoltine, and adults emerge between February and April in synchrony with early-stage host larvae. Adult wasps are relatively short lived (8 days), but survival is increased by access to water and food. Female wasps contain over 6000 eggs at emergence. Aspects of the biology of T. venatoria are discussed in relation to other species of trigonalyid wasps.
Karyotypes of South-West Pacific Ranid Frogs (Anura:Ranidae)
Authors: Mahony MJ , Norris RM , Donnellan SC
Published: June 2005

Karyotypes of 12 species from five genera of Australian, New Guinean and Solomon Islands ranid frogs are reported and for convenience are compared and contrasted with the 2n = 26, fundamental number (FN) = 52 karyotype of Rana, the typical karyotype of the subfamily Raninae. This karyotype was found in the four species of Rana examined. One species, Ceratobatrachus guentheri, had an increased diploid number of 30, a lower FN of 38, and altered relative lengths and centromere positions of pairs 1-5, and several of the smaller pairs. These changes could have resulted from centric fissions and pericentric rearrangements which produced an increase in the number of telocentric chromosomes. Eight species, Batrachylodes vertebralis, Discodeles bufoniformis, D. guppyi, Platymantis boulengeri, P. myersi, P. neckeri, P. solomonis and P. weberi, had reduced diploid numbers and FN. The means by which reduction in diploid number and FN has occurred in these species is unknown, but may involve centric fissions to produce telocentrics, followed by translocation onto other chromosomes, or a process involving pericentric rearrangements to produce telocentric chromosomes followed by fusion of these products. With the exception of Rana, the level of chromosomal rearrangements in the south-west Pacific ranid frogs that occur on archipelagos is high compared with that observed in the continental lineages of this subfamily.
Nest Construction and Recognition in a Gryllacridid: the Discovery of Pheromonally Mediated Autorecognition in an Insect
Authors: Lockwood JA , Rentz DCF
Published: June 2005

The mechanisms of nest building and relocation were examined in Hyalogryllacris sp. 14 (Orthoptera: Gryllacrididae). This nocturnal, thigmotactic species readily constructed silken nests in artificial shelters or 'tents'. The architecture and silk density of nests did not differ significantly between individuals, although nests of males contained significantly more silk that those of females. Disturbing the insects during photophase elicited defensive displays. Gryllacridids reoccupied their original nest significantly more often than an empty tent or the nest of a conspecific, after a night of foraging in a laboratory arena. When offered heat-treated (80 degrees C for 2 h) nests, gryllacridids showed a significant preference for those with greater amounts of silk. The heating (chemical cue elimination), tearing (tactile cue elimination), and heating-tearing of an insect's nest significantly reduced the tendency of the subject to occupy its own nest. Gryllacridids were significantly more likely to occupy nests of conspecifics that had been heat-treated than those that were untreated. They were also significantly more likely to occupy heat-treated nests to which acetone extracts from their own nests had been applied than similar nests treated only with solvent. Thus, individuals of Hyalogryllacris sp. 14 are able to relocate their own nests and avoid those of conspecifics based on a chemical cue. This study provides the first evidence of the capacity for individual or self recognition in insects or other invertebrates through a pheromone or any other sensory modality.
Flower Mites and Phoresy: the Biology of Hattena Panopla Domrow and Hattena Cometis Domrow (Acari:Mesostigmata:Ameroseiidae)
Authors: Seeman OD
Published: June 2005

Two flower-inhabiting ameroseiid mites exhibited different degrees of host specificity; Hattena panopla occurred only in Bruguiera gymnorhiza, but Hattena cometis occurred in Aegiceras corniculatum, Castanospermum australe, Dendrophthoe vitellina, Erythrina variegara, Aloe sp. and Amyema sp. Both species of mite consumed nectar and probably pollen in the laboratory. Flowers of B. gymnorhiza were short lived and senesced after about 5 days. Most H. panopla inhabited the flower for 1-3 days and relied on birds for transport between flowers, but could move from flower to flower via plant stems and were found on ants visiting dying flowers. H. panopla responded to an aging flower by moving out of the petals onto the calyx. All post-larval stages of H. panopla were phoretic; many immature mites of both species dispersed by climbing onto the dorsal surface of dispersing adult mites. The dispersal of immature mites and the behavioural response of H. panopla to flower age were considered to be adaptations to the mite's ephemeral habitat. Adult female H. cometis and adult male and female H. panopla had sucker-like ambulacra that lacked claws, a probable adaptation for phoresy.
Systematics of the Freshwater Crayfish Genus Cherax Erichson (Decapoda: Parastacidae) in Northern and Eastern Australia: Electrophoretic and Morphological Variation
Authors: Austin CM
Published: June 2005

A study of electrophoretic variation amongst 15 putative species of Cherax from northern and eastern Australia supported the recognition of only eight species. Analysis of morphological variation within these crayfish was largely consistent with the taxa identified electrophoretically, although variation in taxonomic characteristics was found to be far more extensive than was previously realised. Of the species identified electrophoretically, only C. dispar Riek and C. rhynchotus Riek are entirely consistent with the most recent taxonomic review of Cherax. The delineation of C. depressus Riek and C. wasselli Riek, although only partially consistent with the accepted geographic distributions of these species, is otherwise similar to the most recent taxonomic treatment. The major taxonomic changes supported by this study involve the delineation of C. cairnsensis Riek, C. cuspidatus Riek, C. destructor Clark and C. quadricarinatus (von Martens). Cherax cairnsensis, which could not be distinguished from the putative C. gladstonensis Riek and, in paa, C. wasselli and C. depressus, is an electrophoretically variable species with an extensive distribution along most of the east coast of Queensland from just north of Calms to just north of Brisbane. The species C. cuspidatus and C. neopunctatus Riek could not be clearly separated from one another and so support a more broadly defined C. cuspidatus. The four species that make up the 'C. destructor' complex (C. albidus Clark, C. davisi Clark, C. destructor Clark and C. esculus Riek) and C. rotundus Clark appear to be part of a single, morphologically variable, species, C. destructor. The redefinition of the northern Australian species C. quadricarinatus to include C. bicarinatus (Gray) from the north-west and C. albertisii (Nobili) from New Guinea is also supported on the basis of both electrophoretic and morphological data. Two species, C. punctatus and C. robustus Riek are more tentatively recognised solely on the basis of morphological evidence.
Seasonal Changes in Digestive Performance of Common Ringtail Possums (Pseudocheirus Peregrinus) Fed Eucalyptus Foliage
Authors: Hume ID , Bladon RV , Soran N
Published: June 2005

Digestive performance of common ringtail possums (Pseudocheirus peregrinus) offered the foliage of Eucalyptus punctata or E. haemastoma was compared in summer and winter. In summer, possums offered E. punctata digested a greater proportion of ingested dry matter, energy, fibre and nitrogen, and remained in positive nitrogen balance, compared with those offered E. haemastoma, which were in slight negative nitrogen balance. In winter, performance on E. punctata was generally similar to that in summer. In contrast, on E. haemastoma in winter, intake of foliage was 24% higher than that of summer foliage and apparent digestibility of energy was 20% higher so that intake of digestible energy was 73% higher, and animals were in strong positive nitrogen balance. Consequently, winter performance measures were nearly all significantly higher on E. haemastoma than on E. punctata. These findings are discussed in terms of me higher nutritive value of young versus mature leaves and the different responses of the two eucalypt species to unusual seasonal conditions. The results demonstrate that seasonal changes in animal performance on eucalypt foliage can be marked, but cannot be used to predict performance in any future year.
Seasonal Changes in the Renal Morphometry of Antechinus Stuartii (Marsupialia: Dasyuridae)
Authors: Mcallan BM , Roberts JR , Oshea T
Published: June 2005

The renal morphology of Antechinus stuartii was examined in males and females in February, May, July and August. Kidney mass was higher in males than females, although the reverse was true when adjusted for body mass. The predicted kidney mass and kidney size calculated from allometric equations were significantly larger than the actual values in males from August, although at other times and for females these values were not different. Relative medullary thickness, percentage medullary thickness and medullary thickness were not different between seasons or sexes. Both superficial and juxtamedullary glomerular volumes increased in July and August in males and this coincided with a reduction in glomerular number per mm(2) of cortex. In general, tubular diameters increased in males in July and August, but not in females. The same was true of cellular volumes from the same sections of the nephron. The renal morphological changes in the males correlate with the life history and endocrine changes of A. stuartii.
Parasitism of Grasshopper and Locust Eggs (Orthoptera: Acrididae) by Scelio Species (Hymenoptera: Scelionidae) in Southern Australia
Authors: Baker GL , Dysart RJ , Pigott RG
Published: June 2005

Surveys of Scelio spp., parasites of acridid eggs, were conducted in southern Australia during 1990-94. Parasitism of economically important grasshopper and locust species was frequently substantial confirming an important, albeit often localised, role by Scelio spp. in regulating host populations. Parasitism of Phaulacridium vittatum eggpods in tableland districts averaged 33.5% +/- s.d. 9.5 (range 27.4-47.1) and Chortoicetes terminifera throughout southern Australia averaged 19.8% +/- s.d. 24.6 (range 0-78.9). Scelio spp. were stenophagous and although some species parasitised several hosts, typically a principal host was readily identifiable. Scelio parvicornis was an exception in having two equally important hosts (P. vittatum and C. terminifera) and several subordinate alternative hosts (Oedaleus australis, Brachyexarna lobipennis and A. vulgaris). New hosts were recorded for S. fulgidus (Gastrimargus musicus), S. chortoicetes (Austroicetes vulgaris), S. parvicornis (Brachyexarna lobipennis, P. vittatum and A. vulgaris), S. flavicornis (C. terminifera), S. sp. nr flavicornis (Praxibulus insolens), S. ignobilis (Aiolopus thalassinus tamulus), S. bipartitus (C. terminifera) and S. orientalis (P. insolens). Significant new geographic distributions include S. parvicornis, S. fulgidus, S. sp. nr improcerus and S. flavicornis from Western Australia and S. orientalis and S. ignobilis from New South Wales. Undescribed species were reared from 29 pods of C. terminifera, P. vittatum, Macrotona australis and P. insolens.
Composition of Milk of the Common Brushtail Possum, Trichosurus Vulpecula (Marsupialia: Phalangeridae): Concentrations of Elements
Authors: Jolly SE , Morriss GA , Scobie S , Cowan PE
Published: June 2005

The concentrations of 11 elements (calcium, copper, iron, magnesium, manganese, phosphorus, potassium, sodium, strontium, sulphur and zinc) were measured in milk samples collected from 193 lactating brushtail possums, Trichosurus vulpecula, at all stages of lactation. Most elements showed patterns of change during lactation similar to those of other marsupials. The most marked changes occurred at about 80-120 days, when the growth rate of the pouch young increased and developmental changes took place, such as eye opening and fur growth. Compared with eutherians, copper and iron concentrations were high in possum milk, as in other marsupials, but zinc levels were exceptionally high. Strontium and manganese levels, not measured before in marsupial milk, were considerably higher than levels reported in eutherian milk. In contrast to eutherian mammals, marsupial young must be supplied with large quantities of minerals in the milk as almost all growth and development occurs after birth, and possum young are entirely dependent on milk supplied by the mother for about the first 100 days.
Within- and Between-Population Variation in Host-Plant Preference and Specificity in Australian Helicoverpa Armigera (Hubner) (Lepidoptera: Noctuidae).
Authors: Jallow MFA , Zalucki MP
Published: June 2005

Using a tethered-insect technique, we investigated within- and between-population variation in the post-alighting host-plant preference and specificity of female Helicoverpa armigera from four populations. No significant difference occurred among populations in host-plant preference. Differences in host-plant preference existed among female moths within a population, and these differences are under genetic control and heritable. Most females ranked maize, sorghum and tobacco highest, followed by cotton varieties DP90 and HG660. The least-preferred plants were cowpea and lucerne. A few females (20%) differed from this general pattern and among each other, and reversed the rank order of host plants. Within a population, individual female moths differed in their host-plant specificity, with some individuals being more generalist than others. Similarly, significant differences occurred in host-plant specificity among populations. The relevance of these findings are discussed in relation to polyphagy in H. armigera.
Allozyme Characterisation of the Salt Lake Spiders (Lycosa: Lycosidae: Araneae) of Southern Australia: Systematic and Population Genetic Implications.
Authors: Hudson P , Adams M
Published: June 2005

Allozyme electrophoresis was used to determine the genetic relationships amongst various populations of Lycosa alteripa, L. eyrei and L. salifodina, the three described species of wolf spider endemic to the normally dry salt lakes of southern Australia. A total of 185 individuals from 38 sites was analysed for allozyme variation at 31-35 loci. The results demonstrate the presence of two additional species of salt lake spider, one related to L. alteripa and the other related to L. eyrei. Limited population genetic analysis of the data indicates that population substructuring is common within most species, often to the finest level of geographic sampling. The data indicate that gene flow is limited in these species and reveal three instances of a similar macro-geographic pattern being displayed amongst subpopulations or taxa in central South Australia. Estimates of genetic divergence between the five taxa have also been used to provide a 'first-guess' estimate of the times of divergence for the major cladogenic events within this lineage.
An Electrophoretic Investigation of Relationships of Diploid and Tetraploid Species of Australian Desert Frogs Neobatrachus (Anura: Myobatrachidae)
Authors: Mahony MJ , Donnellan SC , Roberts JD
Published: June 2005

Allozyme electrophoresis of 27 loci was used to characterise genetic variation among 29 populations of six diploid species of the myobatrachid frog genus Neobatrachus. All six species are well differentiated genetically with the percentage of fixed differences between species ranging from 11 to 59%. The genetic data are in agreement with the currently accepted species boundaries. The four tetraploid species were examined for 25 of the 27 loci assayed in the diploid species. In contrast to the diploid species, the tetraploid species shared electromorphs with each other at all the loci examined. The tetraploid species were examined for the presence of electromorphs specific to individual diploid species. The majority of these electromorphs were observed in the tetraploid species. For cases in which the range of a tetraploid species contacts that of a diploid species and the diploid population can be characterised by unique electromorphs, then evidence of current gene flow was found in the direction of the tetraploid populations. The data are compatible with single or multiple discrete or hybrid origins of the tetraploids overlain by gene flow among the tetraploids and between the tetraploids and some and perhaps all of the diploids by means of geographically limited but ongoing episodes of introgressive hybridisation.
Milk Composition and Production in Free-Living Allied Rock-Wallabies, Petrogale Assimilis
Authors: Merchant JC , Marsh H , Spencer P , Death G
Published: June 2005

Milk composition and the rates of milk consumption by pouch young were examined in free-living allied rock-wallabies, Petrogale assimilis. Milk solids concentrations were approximately 16% (w/w) at 70 days post-partum and increased to about 22% by 170 days when young first left the pouch. By permanent pouch emergence (about 200 days), concentrations had declined and stabilised at about 19%. Milk carbohydrate peaked at 12% (w/v) at 150 days; lipid concentrations averaged 8% (w/w) at 200 days. The subsequent decline in carbohydrates was the main cause of the fall in milk solids. Protein concentrations increased gradually from about 3% (w/v) at 70 days to plateau at 5.5% at about 200 days. Milk consumption rates were measured from 72 to 159 days post-partum with Na-22 turnover. Milk consumption, about 3 mL day(-1) initially, increased to an average of about 15 mL day(-1) by 150 days. The mass gained by a pouch young between 72 and 159 days for each millilitre of milk consumed was not correlated with lactational stage and averaged 0.21 +/- 0.014 (s.e.)g mL(-1).
Phosphorylation-regulated endoplasmic reticulum retention signal in the renal outer-medullary K
+
channel (ROMK)
Authors: O'Connell Anthony D. , Leng Qiang , Dong Ke , MacGregor Gordon G. , Giebisch Gerhard , Hebert Steven C.
Published: June 2005

The renal outer-medullary K
+
channel (ROMK; Kir1.1) mediates K
+
secretion in the renal mammalian nephron that is critical to both sodium and potassium homeostasis. The posttranscriptional expression of ROMK in the plasma membrane of cells is regulated by delivery of protein from endoplasmic reticulum (ER) to the cell surface and by retrieval by dynamin-dependent endocytic mechanisms in clathrin-coated pits. The S44 in the NH
2
terminus of ROMK1 can be phosphorylated by PKA and serum- and glucocorticoid-inducible kinase-1, and this process increases surface expression of functional channels. We present evidence that phosphorylation of S44 modulates channel expression by increasing its cell surface delivery consequent to suppression of a COOH-terminal ER retention signal. This phosphorylation switch of the ER retention signal could provide a pool of mature and properly folded channels for rapid delivery to the plasma membrane. The x-ray crystal structures of inward rectifier K
+
channels have shown a close apposition of the NH
2
terminus with the distal COOH terminus of the adjacent subunit in the channel homotetramer, which is important to channel gating. Thus, NH
2
-terminal phosphorylation modifying a COOH-terminal ER retention signal in ROMK1 could serve as a checkpoint for proper subunit folding critical to channel gating.
Transendothelial Migration of Melanoma Cells Involves N-Cadherin-mediated Adhesion and Activation of the β-Catenin Signaling Pathway
Authors: Qi Jianfei , Chen Ning , Wang Junfu , Siu Chi-Hung
Published: June 2005

Cancer metastasis is a multistep process involving many types of cell-cell interactions, but little is known about the adhesive interactions and signaling events during extravasation of cancer cells. Transendothelial migration of cancer cells was investigated using an in vitro assay, in which melanoma cells were seeded on top of a monolayer of endothelial cells. Attachment of melanoma cells on the endothelium induced a twofold increase in N-cadherin expression in melanoma cells and the redistribution of N-cadherin to the heterotypic contacts. Transendothelial migration was inhibited when N-cadherin expression was repressed by antisense RNA, indicating a key role played by N-cadherin. Whereas N-cadherin and β-catenin colocalized in the contact regions between melanoma cells and endothelial cells during the initial stages of attachment, β-catenin disappeared from the heterotypic contacts during transmigration of melanoma cells. Immunolocalization and immunoprecipitation studies indicate that N-cadherin became tyrosine-phosphorylated, resulting in the dissociation of β-catenin from these contact regions. Concomitantly, an increase in the nuclear level of β-catenin occurred in melanoma cells, together with a sixfold increase in β-catenin-dependent transcription. Transendothelial migration was compromised in cells expressing a dominant-negative form of β-catenin, thus supporting a regulatory role of β-catenin signaling in this process.
Role of the Endocytic Machinery in the Sorting of Lysosome-associated Membrane Proteins
Authors: Janvier Katy , Bonifacino Juan S.
Published: June 2005

The limiting membrane of the lysosome contains a group of transmembrane glycoproteins named lysosome-associated membrane proteins (Lamps). These proteins are targeted to lysosomes by virtue of tyrosine-based sorting signals in their cytosolic tails. Four adaptor protein (AP) complexes, AP-1, AP-2, AP-3, and AP-4, interact with such signals and are therefore candidates for mediating sorting of the Lamps to lysosomes. However, the role of these complexes and of the coat protein, clathrin, in sorting of the Lamps in vivo has either not been addressed or remains controversial. We have used RNA interference to show that AP-2 and clathrin—and to a lesser extent the other AP complexes—are required for efficient delivery of the Lamps to lysosomes. Because AP-2 is exclusively associated with plasma membrane clathrin coats, our observations imply that a significant population of Lamps traffic via the plasma membrane en route to lysosomes.
Intermediate Filaments Interact with Dormant Ezrin in Intestinal Epithelial Cells
Authors: Wald Flavia A. , Oriolo Andrea S. , Casanova M. Llanos , Salas Pedro J.I.
Published: June 2005

Ezrin connects the apical F-actin scaffold to membrane proteins in the apical brush border of intestinal epithelial cells. Yet, the mechanisms that recruit ezrin to the apical domain remain obscure. Using stable CACO-2 transfectants expressing keratin 8 (K8) antisense RNA under a tetracycline-responsive element, we showed that the actin-ezrin scaffold cannot assemble in the absence of intermediate filaments (IFs). Overexpression of ezrin partially rescued this phenotype. Overexpression of K8 in mice also disrupted the assembly of the brush border, but ezrin distributed away from the apical membrane in spots along supernumerary IFs. In cytochalasin D-treated cells ezrin localized to a subapical compartment and coimmunoprecipitated with IFs. Overexpression of ezrin in undifferentiated cells showed a Triton-insoluble ezrin compartment negative for phospho-T567 (dormant) ezrin visualized as spots along IFs. Pulse-chase analysis showed that Triton-insoluble, newly synthesized ezrin transiently coimmunoprecipitates with IFs during the first 30 min of the chase. Dormant, but not active (p-T567), ezrin bound in vitro to isolated denatured keratins in Far-Western analysis and to native IFs in pull-down assays. We conclude that a transient association to IFs is an early step in the polarized assembly of apical ezrin in intestinal epithelial cells.
Geranylgeranyl transferase inhibition stimulates antimelanoma immune response through MHC class I and costimulatory molecule expression
Authors: Tilkin‐Mariamé Anne‐Françoise , Cormary Carine , Ferro Nathalie , Sarrabayrouse Guillaume , Lajoie‐Mazenc Isabelle , Faye Jean‐Charles , Favre Gilles
Published: June 2005

Defective antitumor immune responses are frequent consequences of defects in the expression of major histocompatibility complex (MHC) class I and costimulatory molecules. We demonstrated that statins, inhibitors of HMGCoA reductase, enhance mIFN‐γ induced expression of MHC class I antigens on murine B16F10 melanoma. GGTI‐298, a geranylgeranyl transferase I inhibitor, but not FTI‐277, a farnesyl transferase inhibitor, mimics this effect of statins. This effect is related to peptide transporter protein TAP1 up‐regulation. Simultaneously, GGTI‐298 induces the expression of CD80 and CD86 costimulatory molecules. C3 exoenzyme, which selectively inactivates Rho proteins, phenocopies the effects of GGTI‐298, indicating a role for Rho proteins in these events. Furthermore, the treatment of B16F10 cells with GGTI‐298 or C3 exoenzyme associated with mIFN‐γ induces in vivo tumor growth slowing down in immunocompetent but not in nu/nu syngeneic mice. Both in vivo injections and in vitro restimulation of splenocytes with GGTI‐298‐ and mIFN‐γ‐treated B16F10 cells induces an enhancement of specific CD8 T lymphocytes labeled by TRP‐2/H‐2Kb tetramers. Finally, these effects are not limited to mouse models since they were also reproduced in two human melanoma cell lines. These observations indicate that protein geranylgeranylation as well as Rho protein are critical for costimulatory and IFN‐γ‐dependent MHC class I molecule expression in melanoma.
The Bernal Lecture 2004 Are low-frequency electromagnetic fields a health hazard?
Authors: Crumpton Michael J
Published: June 2005

Electric power is an essential commodity of the developed world, and is critical to the continuing progress of our technology-based society, as well as to the growth of less privileged societies. In contrast to its overwhelming benefits, there is a suspicion that the magnetic component of the electromagnetic fields (EMFs) associated with power distribution and electrical appliances has adverse health effects, especially a small increased incidence of childhood leukaemia. The possibility that environmental EMFs represent a health hazard has serious economic implications for government, the electricity industry and society, as well as raising several profound scientific challenges, including, in particular, biophysical mechanisms, experimental replication and scientific uncertainty. These challenges are explored in relation to the experiences of the EMF Biological Research Trust, a UK medical research charity which funds basic research on the biological effects of extremely low-frequency electromagnetic fields (ELF-EMFs). As judged from these experiences, at the present time there is no compelling experimental evidence that environmental ELF-EMFs induce biological responses.
Solution structure of the ubiquitin‐like domain of human DC‐UbP from dendritic cells
Authors: Gao Yong‐Guang , Song Ai‐Xin , Shi Yan‐Hong , Chang Yong‐Gang , Liu Shu‐Xun , Yu Yi‐Zi , Cao Xue‐Tao , Lin Dong‐Hai , Hu Hong‐Yu
Published: June 2005

The previously identified dendritic cell‐derived ubiquitin‐like protein (DC‐UbP) was implicated in cellular differentiation and apoptosis. Sequence alignment suggested that it contains a ubiquitin‐like (UbL) domain in the C terminus. Here, we present the solution NMR structure and backbone dynamics of the UbL domain of DC‐UbP. The overall structure of the domain is very similar to that of Ub despite low similarity (<30%) in amino‐acid sequence. One distinct feature of the domain structure is its highly positively charged surface that is different from the corresponding surfaces of the well‐known UbL modifiers, Ub, NEDD8, and SUMO‐1. The key amino‐acid residues responsible for guiding polyubiquitinated proteins to proteasome degradation in Ub are not conserved in the UbL domain. This implies that the UbL domain of DC‐UbP may have its own specific interaction partners with other yet unknown cellular functions related to the Ub pathway.
The effect of long‐range interactions on the secondary structure formation of proteins
Authors: Kihara Daisuke
Published: June 2005

The influence of long‐range residue interactions on defining secondary structure in a protein has long been discussed and is often cited as the current limitation to accurate secondary structure prediction. There are several experimental examples where a local sequence alone is not sufficient to determine its secondary structure, but a comprehensive survey on a large data set has not yet been done. Interestingly, some earlier studies denied the negative effect of long‐range interactions on secondary structure prediction accuracy. Here, we have introduced the residue contact order (RCO), which directly indicates the separation of contacting residues in terms of the position in the sequence, and examined the relationship between the RCO and the prediction accuracy. A large data set of 2777 nonhomologous proteins was used in our analysis. Unlike previous studies, we do find that prediction accuracy drops as residues have contacts with more distant residues. Moreover, this negative correlation between the RCO and the prediction accuracy was found not only for β‐strands, but also for α‐helices. The prediction accuracy of β‐strands is lower if residues have a high RCO or a low RCO, which corresponds to the situation that a β‐sheet is formed by β‐strands from different chains in a protein complex. The reason why the current study draws the opposite conclusion from the previous studies is examined. The implication for protein folding is also discussed.
Interaction of serine acetyltransferase with O‐acetylserine sulfhydrylase active site: Evidence from fluorescence spectroscopy
Authors: Campanini Barbara , Speroni Francesca , Salsi Enea , Cook Paul F. , Roderick Steven L. , Huang Bin , Bettati Stefano , Mozzarelli Andrea
Published: June 2005

Serine acetyltransferase is a key enzyme in the sulfur assimilation pathway of bacteria and plants, and is known to form a bienzyme complex with O‐acetylserine sulfhydrylase, the last enzyme in the cysteine biosynthetic pathway. The biological function of the complex and the mechanism of reciprocal regulation of the constituent enzymes are still poorly understood. In this work the effect of complex formation on the O‐acetylserine sulfhydrylase active site has been investigated exploiting the fluorescence properties of pyridoxal 5′‐phosphate, which are sensitive to the cofactor microenvironment and to conformational changes within the protein matrix. The results indicate that both serine acetyltransferase and its C‐terminal decapeptide bind to the α‐carboxyl subsite of O‐acetylserine sulfhydrylase, triggering a transition from an open to a closed conformation. This finding suggests that serine acetyltransferase can inhibit O‐acetylserine sulfhydrylase catalytic activity with a double mechanism, the competition with O‐acetylserine for binding to the enzyme active site and the stabilization of a closed conformation that is less accessible to the natural substrate.
Corticosterone alone does not trigger a short term behavioural shift in incubating female common eiders Somateria mollissima, but does modify long term reproductive success
Authors: Criscuolo François , Chastel Olivier , Bertile Fabrice , Gabrielsen Geir Wing , Maho Yvon Le , Raclot Thierry
Published: June 2005

The trade‐off between reproductive effort and adult survival in birds is modulated by several factors. Corticosterone and prolactin have additive effects on reproductive behaviour by stimulating foraging and parental behaviours, respectively. When incubation is associated with fasting, nest desertion is supposed to be activated by an unknown refeeding signal when body condition becomes critically deteriorated. The concomitant rise in corticosterone levels has been suggested to be the triggering factor. We tested the role of corticosterone on reproductive success by observing the effect of corticosterone implants on reproductive success and on plasma prolactin concentration in female common eiders Somateria mollissima. Implanted females showed a significant increase in corticosterone and a decrease in prolactin levels. Despite their enhanced daily body mass loss, females did not abandon incubation nor did they start to refeed in the four days following implantation. These data show that the experimentally induced rise in plasma corticosterone concentration alone does not trigger nest desertion. However, after 25 days of incubation, implanted females displayed a higher rate of egg loss, suggesting lower nest attentiveness towards the end of incubation. We suggest that the short‐term effects of corticosterone may be dependent on the energy state of the bird. However, the late‐induced change in reproductive success is indirectly linked to corticosterone, and we suggest that either a prolactin decrease, or a depletion in protein body reserves, may participate in the long‐term adjustment of incubation behaviour in female eiders.
Mitochondrial DNA and plumage evolution in the white wagtailMotacilla alba
Authors: Pavlova Alexandra , Zink Robert M. , Rohwer Sievert , Koblik Evgeniy A. , Red'kin Yaroslav A. , Fadeev Igor V. , Nesterov Evgeniy V.
Published: June 2005

We analyzed sequences of two mitochondrial DNA (mtDNA) gene regions (control region and ND2) totaling 1477 base‐pairs from 232 specimens of the white wagtailMotacilla albaobtained from 27 localities throughout Eurasia. Although overall haplotype diversity was relatively low (0.79) and the most common haplotype was shared by 45% of individuals, belonging to six subspecies, a high level of population differentiation was detected. The mtDNA tree revealed three clades: (1) most individuals from Krasnodar (belonging toM. a. albasubspecies), (2) all individuals from Almaty and some from Primor'e (belonging toM. a. personata,M. a. lugensandM. a. leucopsissubspecies), and (3) the remaining individuals (representing all subspecies and all localities except Almaty). We suggest that these three clades represent historically isolated populations that relatively recently came into secondary contact in Krasnodar and Primor'e. None of the six subspecies were reciprocally monophyletic in the mtDNA tree. The Krasnodar population appeared to receive immigrants from other localities, but distinctive haplotypes from this locality did not appear elsewhere, suggesting asymmetric gene flow. Signatures of recent gene flow between northern populations were detected, and there was no evidence of isolation by distance within the northern group of populations. Mismatch distributions for most localities were consistent with population expansions. We also analyzed 12 male plumage characters from 93 study skins sampled from 24 populations. Phylogenetic trees resulting from separate genetic and morphological analyses were incongruent. Plumage evolution seems to be under strong sexual or natural selection, which favors particular phenotypes in various areas irrespective of the mitochondrial background. Dispersal events at different evolutionary times could have obscured the effects of earlier isolation events. The mtDNA data does not support species status forM. a. lugensandM. a. personata, which shared haplotypes with other subspecies ofM. alba. We recommend thatM. lugensandM. personataare placed as junior synonyms ofM. alba.
Raised thermoregulatory costs at exposed song posts increase the energetic cost of singing for willow warblers Phylloscopus trochilus
Authors: Ward Sally , Slater Peter J. B.
Published: June 2005

Sexually selected displays, such as bird song, are expected to be costly. We examined a novel potential cost to bird song: whether a less favourable microclimate at exposed song posts would be predicted to raise metabolic rate. We measured the microclimate and height at which willow warblers Phylloscopus trochilus sang and foraged. Song posts were higher than foraging sites. The wind speed was 0.6±0.3 ms−1 greater at song posts (mean±SD, N=12 birds). Song rate and song post selection were not influenced consistently by temperature or wind speed, but the birds sang from lower positions on one particularly windy day. This may have resulted from difficulty in holding on to exposed branches in windy conditions rather than a thermoregulatory constraint. The results suggest that the extra thermoregulatory costs at song posts would increase metabolic rate by an average of 10±4% and a maximum of 25±8% (N=12 birds) relative to birds singing at foraging sites. We estimated that metabolic rate would be 3–8% greater during singing than during quiet respiration because of heat and evaporative water loss in exhaled gases. The combined energy requirements for sound production, thermoregulation at exposed song posts and additional heat loss in exhaled air could increase the metabolic rate of willow warblers by an average of 14–23%, and a maximum of 42–63%, during singing. The energetic cost of singing may thus be much greater for birds in a cold, windy environment than for birds singing in laboratory conditions.