关键词： MYOGLOBIN   AMINO ACID SEQUENCE   LIOLOPHURA (MOLLUSK)   PHYLOGENETIC TREE  

摘要： Myoglobin was isolated from the radular muscle of the chiton Liolophura japonica, a primitive archigastropodic mollusc. Liolophura contains three monomeric myoglobins (I, II, and III), and the complete amino acid sequence of myoglobin I has been determined. It is composed of 145 amino acid residues, and the molecular mass was calculated to be 16,070 D. The E7 distal histidine, which is replaced by valine or glutamine in several molluscan globins, is conserved in Liolophura myoglobin. The autoxidation rate at physiological conditions indicated that Liolophura oxymyoglobin is fairly stable when compared with other molluscan myoglobins. The amino acid sequence of Liolophura myoglobin shows low homology (11-21%) with molluscan dimeric myoglobins and hemoglobins, but shows higher homology (26-29%) with monomeric myoglobins from the gastropodic molluscs Aplysia, Dolabella, and Bursatella. A phylogenetic tree was constructed from 19 molluscan globin sequences. The tree separated them into two distinct clusters, a cluster for muscle myoglobins and a cluster for erythrocyte or gill hemoglobins. The myoglobin cluster is divided further into two subclusters, corresponding to monomeric and dimeric myoglobins, respectively. Liolophura myoglobin was placed on the branch of monomeric myoglobin lineage, showing that it diverged earlier from other monomeric myoglobins. The hemoglobin cluster is also divided into two subclusters. One cluster contains homodimeric, heterodimeric, tetrameric, and didomain chains of erythrocyte hemoglobins of the blood clams Anadara, Scapharca, and Barbatia. Of special interest is the other subcluster. It consists of three hemoglobin chains derived from the bacterial symbiont-harboring clams Calyptogena and Lucina, in which hemoglobins are supposed to play an important role in maintaining the symbiosis with sulfide bacteria.

关键词： AUSTRALIA   SMALL VERTEBRATES   MALLEE WOODLANDS   FIRE   SERAL RESPONSES  

摘要： The short- and long-term post-fire response patterns of small mammals, reptiles and amphibians inhabiting mallee woodlands and heathlands in temperate Australia are reviewed with respect to species' life history parameters in a search for unifying trends. Pyric response patterns of small mammal species are closely lied to their shelter, food and breeding requirements. There is a trend of increased specificity and reduced flexibility in life history traits concomitant with increased impact of fire and later post-fire recolonization. For reptiles there appears to be a strong relationship between the shelter and foraging requirements of species and their abundance in various successional states. The high incidence of burrowing in the mallee/heath amphibian fauna imparts considerable resilience to fire, and most species' abundance and distribution patterns seem more closely linked to moisture regimes than to fire per se. The high degree of consistency between species' post-fire response patterns and their life history parameters points to the feasibility of developing a model to predict the impact of fire on small vertebrates. Such a model is currently being developed

关键词： BANDICOOT   BETAINE   ECHIDNA   ERYTHROCYTES   H-1 NMR   KOALA   LITTLE PENGUIN   P-31 NMP   PLASMA   TAMMAR WALLABY   TASMANIAN DEVIL   TAURINE   TREE KANGAROO   WOMBAT  

摘要： H-1 and P-32 NMR spectra were acquired from the whole plasma and ultrafiltrates of erythrocytes (RBC) from eight Australian native animals. Various metabolites contained in the samples were identified from their NMR spectra and their concentrations were determined where possible. The key observations were as follows. (1) High lysine concentrations in the RBC from Tammar wallaby (approximately 8 mmol/(L RBC)) were confirmed. (2) A resonance at delta 3.17 in the H-1 spin-echo NMR spectrum of koala RBC was reassigned to the N+-(CH3)3 of betaine and not to ergothioneine as previously claimed. (3) A high concentration (approximately 10 mmol/(L RBC)) of taurine was observed in the RBC from 'little' penguin. (4) The lack of ATP in the RBC of echidna, reported previously on the basis of standard biochemical assays, was confirmed directly by NMR spectroscopy. (5) The highest ergothioneine concentrations in the RBC of the eight species of animal were in the wombat (1.76 mmol/(L RBC)).

关键词： 实验动物   动物模型  

摘要： 自从1981年吴小闲等人将我国的野生树(鼠包)(Tupaia belangeri chinensis)引进实验室饲养繁殖以来,许多研究者把这种新的实验动物用于医学科研,并取得进展。树(鼠包)为小型灵长类动物,其形态、生理机能和生化代谢方面与人相似,作为动物模型可能更接近于人类情况,实验结果容易推广到人。目前,树(鼠包)在甲、乙型肝炎和睡眠生理研究上有重要用途,树(鼠包)还被用作化学致癌、黄曲霉素致肝癌以及人疱疹病毒感染的实验研究,树(鼠包)还被广泛地应用于生态学、形态学、神经生理学、寄生虫学、

摘要： Comparative intestine lengths of 15 Southern African savanna rodents and insectivores are presented. Differences in relative intestine length (ratio between hind gut length to head/body length) between seasons were significant in Aethomys chrysophilus. In various species, breeding females, with their increased energy requirement, had hind gut lengths that were well above average. These females also accounted for the differences between sexes which were significant in two species (Aethomys chrysophilus and A. namaquensis). Within species no correlation was found between relative intestine length and body size (length and weight) of the animals. Between species the correlation was significant and the larger species had relatively longer intestines. Three groups can be distinguished according to the different feeding types of the species. The omnivorous Praomys natalensis has by far the longest intestine. It is followed by a group of species that can be considered as granivore/herbivore. The species that are partly or predominantly insectivorous have the shortest intestine. The results of the field study are found to be in agreement with reports from laboratory experiments concerning adaptations of intestine length to different environmental situations.

摘要： Kava, an intoxicating beverage prepared from the pepper plant Piper methysticum, is widely consumed by the indigenous peoples in the islands of the South Pacific. As the first of a series of studies on the neuropharmacological interactions of kava with CNS receptors we tested purified pyrones and kava resin for activity on GABA and benzodiazepine binding sites in rat and mouse brain membranes. Only weak activity was observed on GABA(A) binding sites in washed synaptosomal membranes prepared from rat brain and this was abolished by extraction of the membranes with Triton X-100, suggesting that lipid soluble components were involved. No effects were observed on GABA(B) binding sites in rat brain membranes in vitro. Kava resin and pyrones exerted some weak effects on benzodiazepine binding in vitro but this did not correlate with pharmacological activity. In addition, in ex vivo studies, no effects were observed on [H-3]diazepam binding to brain membranes prepared from mice in which selected kava constituents were injected intraperitoneally, whereas similarly administered diazepam (5 mg/kg) inhibited [H-3]diazepam binding by > 95%. Similar lack of activity was observed in in vivo binding studies;injection of kava resin failed to influence the CNS binding of the benzodiazepine-receptor ligand [H-3]Ro15-1788 injected into mice prior to sacrifice. The pharmacological activities of kava resin and pyrones do not appear to be explained by any significant interaction with GABA or benzodiazepine binding sites.

关键词： Science   Humanities and Social Sciences   multidisciplinary  

摘要： Recent palaeontological discoveries and the correspondence between molecular and morphological results provide fresh insight on the deep structure of mammalian phylogeny. This new wave of research, however, has yet to resolve some important issues.

关键词： 树Qu   实验动物   哺乳动物  

摘要： 由于树鼩(Tupaia Belangeri,Tree Shrew)在分类学上的特殊地位,近几十年来日本、德国、英国等许多国家研究人员对其生物学、分类学特性进行了大量研究,与此同时,树鼩体小、价廉、新陈代谢远比啮齿类动物更接近人类,在医学科研中应用日渐增多,其作为实验动物的价值也日渐增大。

关键词： OPEROPHTERA-BRUMATA   TORTRIX-VIRIDANA   BUDBURST PHENOLOGY   QUERCUS-ROBUR   POPULATION DYNAMICS   SPATIAL HETEROGENEITY