关键词： Tree frog tadpole   Postembryonic development   Thyroid hormone receptor   Gelatinase B   Proliferating nuclear antigen   Metamorphosis assay  

摘要： The Amphibian Metamorphosis Assay (AMA), developed for Xenopus laevis, is designed to identify chemicals that disrupt thyroid hormone (TH)-mediated biological processes. We adapted the AMA for use on an ecologically-relevant North American species, the Pacific tree frog (Pseudacris regilla), and applied molecular endpoints to evaluate the effects of the antibacterial agent, triclosan (TCS). Premetamorphic (Gosner stage 26-28) tadpoles were immersed for 21 days in solvent control, 1.5 mu g/L thyroxine (T-4), 0.3, 3 and 30 mu g/L (nominal) TCS, or combined T-4/TCS treatments. Exposure effects were scored by morphometric (developmental stage, wet weight, and body, snout-vent and hindlimb lengths) and molecular (mRNA abundance using quantitative real time polymerase chain reaction) criteria. T-4 treatment alone accelerated development concomitant with altered levels of TH receptors alpha and beta, proliferating cell nuclear antigen, and gelatinase B mRNAs in the brain and tail. We observed TCS-induced perturbations in all of the molecular and morphological endpoints indicating that TCS exposure disrupts coordination of postembryonic tadpole development. Clear alterations in molecular endpoints were evident at day 2 whereas the earliest morphological effects appeared at day 4 and were most evident at day 21. Although TCS alone (3 and 30 mu g/L) was protective against tadpole mortality, this protection was lost in the presence of T-4. The Pacific tree frog is the most sensitive species examined to date displaying disruption of TH-mediated development by a common antimicrobial agent. (C) 2012 Elsevier B.V. All rights reserved.

关键词： 小型哺乳动物   灵长类动物   实验动物   生物医学   树鼩   南亚热带地区   亲缘关系   生命周期  

摘要： 树鼩，一类外形似松鼠，生活在东南亚热带地区的小型哺乳动物。树鼩归属于树鼩目（Scandentia），有2科5属共20个种。其中树鼩属（Tupaia）有15个种，为最大的一个属。树鼩属中以北方树鼩（Tupaiabelangern和普通树鼩（聊反科蠡）较为著名。对于树鼩目该被置于食虫目还是灵长目有不少争议。普遍认为树鼩与灵长类动物具有较为接近的亲缘关系，并且还具有一些适合作物实验动物的独特的特点，如成年树鼩较小的体形尺寸，较高的脑体质量比，较短的生殖周期和生命周期，树鼩已被认为可以作为一种灵长类动物的替代动物。过去的十年以来，树鼩作为一种替代动物模型已经广泛地应用与生物医学研究和药物安全试验。

关键词： Elephant   Exclusion   experiment   Nitrogen   Phenol   Plant defence   Tannin  

摘要： We hypothesised that exclusion of long-term browsing leads to decreased nutrient concentrations, increased carbon-based secondary metabolites (CBSMs) and decreased shoot length in woody plants in semi-arid savannas. To test this, we sampled four deciduous woody species in a large-scale, long-term exclusion experiment. We found a tendency for large herbivore exclusion to either decrease nitrogen or increase tannin in two tree species. Phosphorus and total polyphenol responses indicated complex interactions with herbivore assemblage. Shoot length decreased under exclusion in two species, while a similar tendency existed in the remaining species. Therefore, we found limited support for our predictions that exclusion of browsing results in reduced nitrogen or increased CBSMs, but moderate support for decreased shoot length in semi-arid savannas. Dichrostachys cinerea, a fast-growing, aggressive invader in savannas, displayed C-limitation with removal of large herbivores because both shoot length and CBSMs decreased. In conclusion, effects of long-term browsing on deciduous trees in semi-arid savannas depend on the plant species, specific nutrients or CBSMs measured and the composition of the herbivore assemblages. Because elephant densities in the study area were high and most responses were associated with their exclusion, we conclude that elephants are important drivers of browse quality in the study area. (c) 2012 Elsevier Ltd. All rights reserved.

关键词： Beetles   Coleoptera   oak trees   Quercus robur   seasonality   species richness   temporal partitioning  

摘要： 1. Species richness, abundance, body size, biomass, guild structure and temporal partitioning were examined in samples of 150 beetle species from oaks (Quercus robur L.) in southern Britain. 2. Abundance, species richness and biomass were highest in late June when leaves are in full flush, similar through much of the year for oak specialist beetle species, but were highest in July for generalists. Body size did not appear to vary significantly during the sampling period. 3. Temporal partitioning of feeding guilds was evident;predators and herbivores, peaked earlier in MayJune, and fungivores and scavengers peaked in JulyAugust. 4. Groups of closely related species, in Carabidae, Cantharidae and Curculionidae, often had similar seasonal patterns suggesting that temporal variation in both overall species richness and abundance for different guilds may be driven by resource availability rather than competition between closely related species. 5. Multidimensional scaling ordination shows an almost circular pattern in the beetle community underpinned by the most abundant species occurring throughout the year;vector analysis indicates that as temperatures increase and food resources become available, other species become abundant and influence patterns of similarity. 6. These patterns are also influenced by species that (i) have life cycles of 2 or more years, (ii) move between the ground, tree trunks and the canopy during the year and (iii) move from other tree species to oaks as these tree species lose their leaves earlier in Autumn. 7. The hypothesis that temporal patterns for invertebrate species in temperate trees are more coordinated than those in tropical trees is not supported.

关键词： lophophorates   Lophotrochozoa   Metazoa   systematics  

摘要： Molecular phylogenetics has resulted in conflicting accounts of the relationship between phoronids and brachiopods. Taxonomically comprehensive analyses of brachiopod and phoronid ribosomal DNA sequences (rDNAs) rooted with short-branched mollusc sequences uniformly find that phoronids nest within brachiopods as the sister of the three extant inarticulate lineages. Here, this is called the alternate topology because it does not match traditional, morphology-based ideas. Many other analyses of protein-coding genes and/or rDNAs place phoronids elsewhere, often as the sister group of all brachiopods, better matching traditional ideas. However, these analyses generally are based on data from small selections of brachiopods and phoronids, include data from a wide range of other metazoan taxa, and are rooted with distant outgroups. Here, I show that outgroup rooting of brachiopods and phoronid rDNAs is unreliable, and instead find the root position with procedures that are free from all distortions caused by distantly related taxa, i.e. by Bayesian and maximum likelihood relaxed-clock analyses of a purely ingroup alignment. All such analyses confirm the alternate topology: phoronids belong within the Brachiopoda as the sister group of the inarticulates. In addition, nine factors are identified that (singly or in combination) can cause misreporting of the phylogenetic signal in wide taxon-range analyses of both rDNA and amino acid sequence data. (C) 2012 The Linnean Society of London, Zoological Journal of the Linnean Society, 2013, 167, 82-92. doi: 10.1111/j.1096-3642.2012.00869.x

关键词： Associational resistance   Insect herbivores   Plant apparency   Restoration   Smallholder forestry   Timber plantations  

摘要： The reforestation of degraded tropical pastures requires innovative tree planting systems that consider land user needs. We established a silvopastoral reforestation system and assessed the effects of companion trees on the native timber tree Tabebuia rosea in Panama. Timber tree individuals were established in (1) solitary plantings (TSol) or in companion plantings with (2) Guazuma ulmifolia (TGua) or (3) the nitrogen-fixing Gliricidia sepium (TGli). We quantified growth characteristics and herbivory of T. rosea, and analyzed leaf chemistry (including the stable isotopes delta N-15 and delta C-13) and structure (leaf mass per area). Companion trees significantly affected stem diameter growth of T. rosea. Stem diameter growth was as high in TGli trees as in TSol trees but was reduced in TGua trees. Furthermore, TGua trees had higher leaf water content, and lower delta C-13 and lower leaf mass-to-area ratio than TGli trees, suggesting there were effects of shading by G. ulmifolia on T. rosea. Herbivory was high but not affected by planting regimes. Leafing phenology did not differ between planting regimes and G. sepium did not increase nitrogen content in T. rosea leaves. Companion tree planting can support timber tree growth in silvopastoral reforestations, but adequate species selection is crucial for successful implementation of this planting system. Tree-tree interactions seem to be more relevant for timber tree growth than herbivory in the studied system.

关键词： Nest boxes   New Guinea   tree cavity   wildlife management  

摘要： Little is known of the frequency of use and reliance upon tree cavities by wildlife, nor the natural availability of cavities in New Guinea forests. We surveyed the literature for records of cavity use by birds and mammals in New Guinea. We examined every standing tree on one hectare of primary forest and one hectare of secondary forest for cavities, then carefully assessed every tree for cavities after they were felled. We put up 190 artificial nest boxes of five designs in three sites and monitored occupancy. At least 50 species (23.6%) of New Guinea terrestrial mammals and 118 species (17.7%) of non-marine or aquatic bird species are recorded in the literature as using tree cavities. Ground observation identified 36 suspected cavities in a hectare of lowland primary forest and 10 in nearby secondary forest. Upon inspection of all trees after felling, these figures changed to 26 and 0 respectively. Ground censuses are not accurate. Cavities were more commonly found in large trees. In less than a year, nest box occupancy reached exceeded 33%, with Phalanger spp. and Sugar gliders, Petaurus breviceps, being most common. Some bird use was detected by the presence of feathers;snakes and geckos were also found in boxes. Occupancy increased with time and would probably be higher after a second year. The larger boxes had greater occupancy, as did boxes placed higher in the trees. Bees occupied and probably excluded other users from 10% of boxes. As Papuan forests are disturbed by logging, hunting practices and gardening, conservationists might need to manage practices to ensure cavity availability. Artificial nest boxes might have utility for wildlife conservation and research.

关键词： Chronic renal disease   Plasma phosphate concentration   Proteinuria   Obesity   Diabetes   Colon carcinoma   Inflammation  

摘要： Gum arabic (GA), a water-soluble dietary fiber rich in Ca2+, Mg2+ and K+, is used in Middle Eastern countries for the treatment of patients with chronic kidney disease. Recent animal experiments shed some light into mechanisms involved in the therapeutic action of GA. According to experiments in healthy mice, GA treatment increases creatinine clearance, enhances renal excretion of ADH, Mg2+ and Ca2+, decreases plasma phosphate concentration as well as urinary excretion of phosphate and Na+. In diabetic mice GA treatment increases urinary Ca2+ excretion, and decreases plasma phosphate concentration, plasma urea concentration, urinary flow rate, natriuresis, phosphaturia, glucosuria, proteinuria as well as blood pressure. Extrarenal effects of GA treatment in mice include decreased expression of intestinal Na+ coupled glucose carrier SGLT1 with subsequent delay of electrogenic intestinal glucose transport, glucose-induced hyperglycemia, hyperinsulinemia and body weight gain. GA treatment decreases colonic transcription of the angiogenetic factors angiogenin 1, angiogenin 3 and angiogenin 4, of CD38 antigen, aquaporin4, interleukin18, vav-3-oncogene, y(+)-amino acid-transporter, sulfatase1, ubiquitinD and chemokine ligand5. Moreover, GA treatment decreases angiogenin and beta-catenin protein expression. Accordingly, GA treatment counteracts the development of tumors following chemical cancerogenesis. In mouse dendritic cells, antigen-presenting cells linking innate and adaptive immunity, GA treatment modifies maturation and cytokine release. GA treatment further favourably influences the course of murine malaria. The effects of GA treatment on plasma phosphate concentration, blood pressure and proteinuria may prove beneficial in chronic renal failure and diabetic nephropathy. The effect of GA on intestinal glucose transport may be useful in the prophylaxis and treatment of obesity and diabetes, the effect of GA on angiogenin and beta-catenin expression could be exploit

关键词： 树鼩   灵长类   动物模型   人类疾病   基因组   染色体组   重点实验室  

摘要： 由中科院昆明动物所动物模型与人类疾病机理重点实验室、深圳华大基因研究院等单位合作完成的破译树鼩基因组研究工作于2013年2月在《自然·通讯》(Nature Communications)杂志上在线发表。研究人员通过完成高质量的树鼩(Tupaia belangeri chinensis)全基因组测序及比较基因组分析,阐明了其系统分类地位和相关生物学特征的遗传基础,尤其是树鼩用于若干重要疾病如HBV、HCV感染以及抑郁症模

关键词： Taxonomy   Phoridae   new species   Kola Peninsula  

摘要： 64 species of Phoridae, in 6 genera, are reported from the Kola Peninsula, north of the Arctic Circle. The new species Megaselia elenae and M. kozlovi are described. 33 species of Megaselia, only known from females, are given code numbers. Keys to the species of all the females of Megaselia and Phora are provided;and also a key to the males European Megaselia species with a notopleural cleft.