关键词： Heterogeneity   Haplodiploid   Pikonema alaskensis   Phenology   Picea mariana   YELLOWHEADED SPRUCE   PIKONEMA-ALASKENSIS   FUCUS-VESICULOSUS   FEEDING-BEHAVIOR   WHITE SPRUCE   HOST   LEPIDOPTERA   GROWTH   STRATIFICATION   HYMENOPTERA  

摘要： Some herbivorous insects enhance their fitness using foraging strategies that allow them to find and colonize the best of available resources within heterogeneous plants. The yellowheaded spruce sawfly, Pikonema alaskensis (Roh.) (Hymenoptera: Tenthredinidae), is a common defoliator that oviposits and feeds on the developing foliage of young open-grown black spruce [Picea mariana (Mills) B.S.P.]. While female and male eggs are both laid throughout the crown, most eggs laid in the upper crown are female, and more female than male late-instar larvae disperse acropetally, from the lower and mid-crown to the upper crown, to complete juvenile development. Here we present results from 4 years of manipulative sleeve-cage experiments that were carried out to evaluate the hypothesis that sex-biased oviposition-site selection and acropetal dispersal by P. alaskensis are adaptive responses to intra-tree variation in foliage quality. Survival and proportion of survivors that were female were either the same (2 years) or significantly higher (2 years) for groups placed in the lower or mid-crown during early instars, and then transferred acropetally during late instars to complete development in the upper crown, compared with those forced to feed exclusively in the lower crown. This suggests that females benefited most from acropetal dispersal. Sex ratios of survivors that had been forced to develop exclusively in the upper crown were usually more female biased than those of survivors that developed exclusively in the lower crown, suggesting higher survival for female than for male larvae emerging from eggs laid in the upper crown. Sex-biased egg allocation and larval dispersal appear to increase the survival of P. alaskensis by accounting for differential effects on male versus female larvae of phenology-independent temporal and spatial variations in the quality of foliage within the heterogeneous crown of black spruce.

关键词： arthropod phylogeny   molecular phylogenetic tree reconstruction   Myriochelata   Pancrustacea   phylogenomics   COMPLETE MITOCHONDRIAL GENOME   INTRON POSITIONS   HEXAPOD ORIGINS   PHYLOGENY   DNA   EVOLUTION   PATTERN   SUPPORT   GENES   SEQUENCE  

摘要： Deep-level arthropod phylogeny has been in a state of upheaval ever since the emergence of molecular tree reconstruction approaches. While a consensus has settled in that hexapods are more closely related to crustaceans than to myriapods, the phylogenetic position of the latter has remained a matter of debate. Mitochondrial, nuclear, and genome-scale studies have proposed rejecting the long-standing superclade Mandibulata, which unites myriapods with insects and crustaceans, in favor of a clade that unites myriapods with chelicerates and has become known as Paradoxapoda or Myriochelata. Here we discuss the progress, problems, and prospects of arriving at the final arthropod tree.

关键词： 家园   动物   青梅竹马  

摘要： 小考拉和小蓝鸟是一对青梅竹马的好朋友。

关键词： 支气管败血波氏杆菌   Biolog   16S   rRNA   系统发育分析  

摘要： 采用Biolog和16SrRNA基因序列分析法对分离自北京动物园的8株支气管败血波氏杆菌进行了鉴定。菌株经纯化培养,用Biolog微生物鉴定系统进行了鉴定,结果表明,8株菌株为支气管败血波氏杆菌。菌株经纯化培养,采用菌落PCR方法进行16SrRNA基因序列扩增,扩增产物纯化后直接进行测序。序列经人工校对后用ClustalX1.83软件进行比对分析,最后用Mega3.1软件构建系统发育树,系统发育分析结果表明,8株菌株与支气管败血波氏杆菌DSM10303的同源性达到了99.9%,并在同一个分支内。

关键词： 树鼩   地塞米松   链脲佐菌素   2型糖尿病  

摘要： 本实验分为两部分,第一部分为高脂高糖饲料联合地塞米松诱导树鼩糖脂代谢异常动物模型;第二部分为小剂量链脲佐菌素多次注射诱导树嗣2型糖尿病动物模型。 第一部分目的用高糖高脂饲料+地塞米松(dexamethasone, DEX)联合诱导树鼩糖代谢和脂代谢紊乱,为建立实验性2型糖尿病树鼩模型提供前期基础。方法14只雄性中缅树鼩,随机分为高糖高脂组(HGF,n=6)和高糖高脂+DEX组(HGF+DEX,3mg/kg, h.i, n=8),于给药前后分别测定空腹血糖(FBG)、体重、甘油三酯(TG),总胆固醇(TC),糖化血红蛋白(HbAlc);成模实验动物取胰腺,肾脏,肝脏等组织做常规HE染色,光镜下观察其病理变化。结果HGF组无一成膜,HGF+DEX组给药后第3周空腹血糖(FBG)就显著升高,维持两周后下降,但第7周又升高。同时发生脂代谢紊乱,糖耐量异常且两组体重都下降。HGF+DEX组的树鼩胰腺常规HE染色发现胰岛数量明显减少,体积变小,胰岛β细胞数量减少,肿胀;部分肾小管上皮细胞萎缩、脂肪变性,肾小管管腔扩张,钙化,并可见蛋白管型,肾间质充血;肝细胞不同程度脂肪变性。结论高糖高脂+地塞米松连续多次腹腔注射可诱发树鼩糖代谢、脂代谢紊乱。 第二部分目的探索链脲佐菌素(Streptozotocin, STZ)诱导树鼩2型糖尿病动物模型的方法。方法22只雄性中缅树鼩,随机分为正常对照组(NC, n=6)、STZ组(120mg/kg, i.p,n=8)和DEX+STZ组(n=8)。连续观察15周,测定FBG、体重、TG和TC;在血糖明显升高并维持两周以上时做口服葡萄糖耐量试验(OGTT)。将FBG≥10.0mmol/L并维持两周以上且血脂与本组给药前相比有显著差异者视为成膜动物。并于实验结束时取成模实验动物胰腺,肾脏,肝脏等组织做常规HE染色,光镜下观察其病理变化。结果正常对照组(NC)组无一成膜;STZ组成膜率为100%,一只动物在OGTT实验中由于血糖过高而死亡(第7周),死亡率为12.5%(1／8)。成模树鼩具有胰岛素抵抗、高血糖、血脂紊乱的T2DM临床特征,高血糖持续时间最长、最稳定(到实验结束模型稳定至少80 d)。光镜下观察病理切片,FBG≥10.0mmol/L的树鼩胰腺常规HE染色中胰岛数量明显减少,胰岛萎缩,体积变小,胰岛界限不清晰;肾脏组织切片可见肾间质充血,肾小管上皮细胞水肿变性,有淋巴细胞浸润;肝脏最典型的变化是脂肪变性。结论以120mg/kg剂量腹腔注射STZ多次后能够快速诱导树鼩形成T2DM,是一种较好的制备树鼩T2DM的方法。

关键词： biodiversity   ecological indicators   green-tree retention   small mammals   mountain pine beetle   Pinus contorta   Pseudotsuga menziesii   salvage harvest   stand structure   NORTHERN FLYING SQUIRREL   MOUNTAIN PINE-BEETLE   RED-BACKED VOLE   FOREST ECOSYSTEMS   PACIFIC-NORTHWEST   POPULATION-DYNAMICS   SIZE DIVERSITY   FIR FORESTS   MANAGEMENT   LANDSCAPE  

摘要： We report on a retrospective investigation of the impacts of salvage harvesting of lodgepole pine (Pinus conform var. latifolia Engelm. ex S. Wats.), killed by an outbreak of mountain pine beetle (Dendroctonus ponderosae Hopk.) in the 1970s, with variable retention of Douglas-fir (Pseudotsuga menziesii (Mirbel) Franco). Our inference to biodiversity was coniferous stand structure and four mammal species: the southern red-backed vole (Myodes gapperi Vigors), common shrew (Sorex cinereus Kerr), red squirrel (Tamiasciurus hudsonicus Erxleben) and northern Hying squirrel (Glaucomys sabrinus Shaw). We tested hypotheses that, at 30 years after salvage harvest of beetle-killed lodgepole pine trees, (1) abundance and diversity of stand structure, and (2) abundance of mammal species, will increase with higher levels of green-tree retention (GTR). Stand structure attributes and small mammals were sampled during 2005-2008 in young pine stands, with a range of GTR seed-trees (none, dispersed, and aggregated Douglas-fir), and uncut forest in south-central British Columbia, Canada. Diameters and heights of Douglas-fir and lodgepole pine and basal area of total conifers supported hypothesis (1). Mean abundance of the red-backed vole was consistently higher (2.3 to 6.4 times) in the uncut forest than other stands. Overall mean patterns of abundance for common shrews, red squirrels, and northern flying squirrels were similar among treatment stands. Mean abundance of the red-backed vole supported hypothesis (2), but numbers of the other three species did not. There is "life after the beetle" at 30 years after salvage harvesting, and this was enhanced by GTR.

关键词： 脊椎动物   晚二叠世   树栖   陆地生态系统   生活环境   食物来源   生态空间   猎食  

摘要： 纵贯脊椎动物在陆地上的历史，它们不断地填充和分割着陆地生态系统，不断占据新的、先前未曾开发过的生活环境。由于树冠能提供新的食物来源和保护它们免受地面猎食者的捕杀，树栖生态空间对脊椎动物的进化显得很重要。

关键词： 树鮈   资源开发   标准化研究  

摘要： 树鮈(Tupaia belangeri)作为人类疾病动物模型,被应用于人类医学实验研究的多个领域,如各种类型的病毒性肝炎模型,流感病毒、登革热病毒、轮状病毒、疱疹病毒模型,糖尿病、胆结石、癌症病模型。但是,目前我国用于实验研究的树鮈几乎全都来自野外,对它们的微生物学、寄生虫学、遗传学、环境学等质量标准没有进行控制,它们本身携带的许多病原体会对实验结果的准确性造成影响,这既不符合国家对实验动物许可证管理的要求,也不利于我国实验动物科技工作与国际接轨的发展要求。因此,应该同步开展树鮈资源的开发利用和标准研究,使之纳入实验动物许可证的有效监控和管理,改变目前使用在前、质量控制标准研究在后的被动局面。

关键词： dispersal limitation   Ecuador   frugivory   fruit removal   primates   seed dispersal   toucans   tropical forest   Virola flexuosa   TROPICAL FORESTS   ABUNDANCE   HARVEST  

摘要： To understand how different frugivores impact dispersal, we studied the assemblage that feed on Virola flexuosa over a two-year period at two sites differing in hunting pressure in Ecuador. We focus on disperser effectiveness and test the hypothesis that seed removal, influenced by differential visits of large-bodied frugivores, will differ between hunted and non-hunted sites. All visiting frugivores were identified, and fruit handling behavior and seed removal rates quantified. Seed traps were placed under fruiting trees to estimate crop size and fruit removal. Seventeen bird and three primate species were recorded foraging in V. flexuosa trees. Toucans and primates were the most important dispersers comprising nearly 85% of visits with six toucan species recorded in 74% of visits. A proportionately larger number of seeds were removed from fruiting trees at a non-hunted site (89.4%) than a hunted site (66.8%). In addition, there were significantly more frugivore visits at the non-hunted than the hunted site. The differences in the frugivore assemblage and the number of seeds dispersed from individual trees between two structurally similar forest sites suggest dispersal limitation resulting from a decline in frugivores.

关键词： Diversity-functioning relationships   Leaf damage   Mines   Multitrophic interactions   Plant-animal interactions   SPECIES-DIVERSITY   ASSOCIATIONAL RESISTANCE   VEGETATIONAL DIVERSITY   ENEMIES HYPOTHESIS   INSECT HERBIVORES   BOREAL FORESTS   SILVER BIRCH   PINE STANDS   BIODIVERSITY   GROWTH  

摘要： Tree species-rich forests are hypothesised to be less susceptible to insect herbivores, but so far herbivory-diversity relationships have rarely been tested for tree saplings, and no such study has been published for deciduous forests in Central Europe. We expected that diverse tree communities reduce the probability of detection of host plants and increase abundance of predators, thereby reducing herbivory. We examined levels of herbivory suffered by beech (Fagus sylvatica L.) and maple saplings (Acer pseudoplatanus L. and Acer platanoides L.) across a tree species diversity gradient within Germany's largest remaining deciduous forest area, and investigated whether simple beech or mixed stands were less prone to damage caused by herbivorous insects. Leaf area loss and the frequency of galls and mines were recorded for 1,040 saplings (> 13,000 leaves) in June and August 2006. In addition, relative abundance of predators was assessed to test for potential top-down control. Leaf area loss was generally higher in the two species of maple compared to beech saplings, while only beech showed a decline in damage caused by leaf-chewing herbivores across the tree diversity gradient. No significant patterns were found for galls and mines. Relative abundance of predators on beech showed a seasonal response and increased on species-rich plots in June, suggesting higher biological control. We conclude that, in temperate deciduous forests, herbivory-tree diversity relationships are significant, but are tree species-dependent with bottom-up and top-down control as possible mechanisms. In contrast to maple, beech profits from growing in a neighbourhood of higher tree richness, which implies that species identity effects may be of greater importance than tree diversity effects per se. Hence, herbivory on beech appeared to be mediated bottom-up by resource concentration in the sampled forest stands, as well as regulated top-down through biocontrol by natural enemies.