暗腹雪鸡与藏雪鸡羽毛显微结构比较

羽毛是鸟类特有的皮肤衍生物,鸟羽显微结构具有较强的稳定性和种间特异性,鸟羽显微结构特征,可为鸟类物种的鉴定提供依据。应用扫描电镜对暗腹雪鸡(Tetraogallus himalayensis)与藏雪鸡(Tetraogallus tibetanus)的飞羽、绒羽和尾羽的显微结构进行观察。结果表明:飞羽和尾羽主要由有钩羽小枝和无钩羽小枝构成;绒羽主要由节状羽小枝构成。对飞羽和尾羽的羽小钩数、纤毛数、腹齿数以及绒羽的节直径、节间距和基节长进行显著性分析,发现尾羽的羽小钩数、纤毛数、腹齿数、绒羽的节直径与基节长在二者间差异显著,而绒羽的节间距和飞羽的几个指标在二者间差异均不显著。利用羽毛的显微结构来区分暗腹雪鸡与藏雪鸡时,尾羽的羽小钩数、纤毛数、腹齿数和绒羽的节直径、基节长是对二者进行识别的可选指标。     

黑耳鸢羽毛的扫描电镜观察

羽毛是鸟类案件现场比较容易获得的一类物证,本研究选取黑耳鸢的飞羽、尾羽、体羽和绒羽,利用扫描电镜对其显微结构进行观察.结果表明:黑耳鸢的飞羽、体羽和尾羽均由有钩羽小枝和无钩羽小枝组成,绒羽主要由节状羽小枝组成.飞羽、尾羽和体羽的有钩羽小枝的羽小钩数和纤毛数以及绒羽的节状羽小枝的节直径、节间距和节基长均不尽相同.与相关研究进行比较表明几类羽毛的各项指标在不同的物种间存在或多或少的差异,可以为通过羽毛对物种进行鉴别提供依据.     

红角鸮、斑头鸺鹠和黄腿渔鸮尾羽的观察与比较

选择鸮形目鸱鸮科的红角鸮、斑头鸺鹠和黄腿渔鸮的尾羽中正羽和绒羽进行测量与扫描电镜观察,并记录正羽羽片长度、宽度和羽干长度以及绒羽节状羽小枝的基节长度和节间距,然后进行数据分析.结果表明这3种鸟类尾羽中正羽的羽片宽度和羽干长度有显著差异,尾羽中绒羽的节状羽小枝基节长度和其他节长度均具有极显著差异.通过尾羽的正羽羽片宽度和羽干长度以及绒羽的羽小枝特征差异可以比较鉴别这3种鸟类.     

10种隼形目鸟类尾羽羽小枝扫描电镜观察

选择10种隼形目鸟类尾羽,利用扫描电镜观察其显微结构,同时测量中央尾羽内、外翈宽度。结果表明:有钩羽小枝的羽小钩数,纤毛的粗细、长短、数量,腹齿数,无钩羽小枝的腹齿数以及羽小枝末端是否呈节状等特征在不同种类间存在差异。单因素方差分析表明中央尾羽内、外翈宽度的比值在某些种类间存在差异,用于显微结构分析的3个指标在2个物种间至少有1个指标差异显著。     

白鹭脱落羽毛的微卫星个体识别研究

利用鹭科鸟类已有微卫星引物进行跨种扩增筛选,获得12对可用于白鹭(Egretta garzetta)的微卫星引物,结合非损伤采集的脱落羽毛样品,在物种分子鉴定和性别分子鉴定的基础上,建立适用于羽毛样品个体识别分析的微卫星基因分型技术体系.在中国沿海的3个白鹭繁殖种群的181样品中,19个羽毛样品由于DNA质量较差未能有效鉴定物种.119个羽毛样品成功地鉴定为白鹭个体,物种鉴定结果可重复率达93.8%.性别鉴定结果可重复率94.1%,119个白鹭羽毛样品当中的28.57%为雄性.基因分型得到各个位点的等位基因数7~22个,观察杂合度和期望杂合度分别为0.623~0.875和0.779~0.918,没有位点偏离哈迪-温伯格平衡,基因分型错误率为1.2%.个体识别分析发现其中的2个样品为相同基因型,为重复采集自同一个体脱落的不同羽毛.本研究结果将为深入研究白鹭种群遗传结构、扩散模式等保护遗传学问题奠定了基础,并且能够为其他鹭科鸟类的脱落羽毛的物种鉴定、性别鉴定、个体识别提供参考.     

白鹭和大白鹭羽毛显微结构观察

【目的】探讨鸟类羽毛微观结构的差异,并据此鉴别鸟类。【方法】选取白鹭(Egretta garzetta)和大白鹭(E. alba)的飞羽、胸羽、尾羽及蓑羽4类羽毛作为研究对象,利用扫描电镜观察4类羽毛的羽小钩、腹齿及纤毛等微观结构的数量,利用SPSS 18.0对所观察的数据进行分析比较。【结果】飞羽中除腹齿数外,有钩羽小枝基柄长、羽小钩数、纤毛数以及无钩羽小枝基柄长在白鹭和大白鹭间均存在极显著差异;胸羽和尾羽有钩羽小枝的基柄长、腹齿数、羽小钩数、纤毛数以及无钩羽小枝的基柄长和腹齿数在白鹭和大白鹭间均存在显著或极显著差异;蓑羽纤毛数和基柄长在白鹭和大白鹭间存在极显著差异。【结论】除飞羽的腹齿外,所选的其他指标均可为白鹭和大白鹭的鉴别提供参考。     

纵纹腹小鸮

我国地域广博,生境多样,鸟类资源也相当丰富,有鸟类1244种。众所周知,鸟中有一类主要活动于夜晚,以老鼠为主食,是老鼠的天敌,是生态系统内食物链中处于最高能量级的类群——即猫头鹰。所谓的“猫头鹰”是所有鸮形目种类的统称,是一类夜行性猛禽,由于其外观似猫而得名。我国鸮形目鸟类有27种,占世界鸮类的20%左右,分隶于草鸮科     

鸽子羽毛微观结构的研究

鸟羽根据其主要特征可以分为正羽,绒羽和纤羽．正羽又包括飞羽,尾羽．本文主要是通过显微镜观察鸽子的飞羽,尾羽的微观结构进行观察研究,结果表明：具有飞翔功能的飞羽、尾羽主要是由有钩羽小枝、无钩羽小枝两种构成;而不具有飞翔功能的绒羽主要由节状羽小枝构成．羽轴的表面盖为多边形的角质花纹,而髓质层则是由多孔的髓腔构成的．     

安徽省鸟类新纪录——黄嘴角鸮

2022年8月7日晚，笔者在黄山市黄山区汤口镇浮溪村（30.085 1N,118.145 8E，海拔562m）进行生物多样性调查时，观察并记录到鸮形目鸟类2只．通过对其鸣声和形态辨识并查阅资料文献，确定其为黄嘴角鸮（Otus spilocephalus）．该物种为安徽省鸟类新纪录，此记录也是该物种目前分布最北界的记录．     

封面故事

雪鸮（Bubo scandiacus）又名白鸮、雪猫头鹰、白夜猫子,是鸮形目鸱鸮科的一种大型猫头鹰。最初由瑞典自然学家卡尔·林奈于1758年分类。雪鸮因全身几乎为雪白色而得名,而且它们多为昼行性鸟类,是很有特点的一种猫头鹰。     

The morphogenesis of feathers

Feathers are highly ordered, hierarchical branched structures that confer birds with the ability of flight. Discoveries of fossilized dinosaurs in China bearing 'feather-like' structures have prompted interest in the origin and evolution of feathers. However, there is uncertainty about whether the irregularly branched integumentary fibres on dinosaurs such as Sinornithosaurus are truly feathers, and whether an integumentary appendage with a major central shaft and notched edges is a non-avian feather or a proto-feather. Here, we use a developmental approach to analyse molecular mechanisms in feather-branching morphogenesis. We have used the replication-competent avian sarcoma retrovirus to deliver exogenous genes to regenerating flight feather follicles of chickens. We show that the antagonistic balance between noggin and bone morphogenetic protein 4 (BMP4) has a critical role in feather branching, with BMP4 promoting rachis formation and barb fusion, and noggin enhancing rachis and barb branching. Furthermore, we show that sonic hedgehog (Shh) is essential for inducing apoptosis of the marginal plate epithelia, which results in spaces between barbs. Our analyses identify the molecular pathways underlying the topological transformation of feathers from cylindrical epithelia to the hierarchical branched structures, and provide insights on the possible developmental mechanisms in the evolution of feather forms.     

鸭的羽毛组成成分比较分析

用氨基酸分析仪测定北京鸭、金定鸭及其杂种大土北鸭羽毛的氨基酸组成,发现不同种的鸭毛所含的氨基酸种类相同,但相应的各种氨基酸的含量却有差别。大土北鸭羽毛的异亮氨酸、甲硫氨酸和脯氨酸的含量接近于北京鸭;半胱氨酸、谷氨酸(包括谷氨酰胺)、甘氨酸、亮氨酸、苯丙氨酸和酪氨酸的含量接近于金定鸭;天冬氨酸(包括天冬酰胺)的含量略低于两亲本;赖氨酸的含量显著低于两亲本;丙氨酸、精氨酸、组氨酸、苏氨酸和缬氨酸的含量高于两亲本;丝氨酸的含量则与两亲本相近。经光谱分析表明,三种鸭毛所含金属元素的种类亦相同,且铜含量相差无几;北京鸭羽毛的锌、铁含量明显高于金定鸭;大土北鸭羽毛的锌含量接近于金定鸭,而铁含量则接近于北京鸭。     

Mapping stem cell activities in the feather follicle

It is important to know how different organs 'manage' their stem cells. Both hair and feather follicles show robust regenerative powers that episodically renew the epithelial organ. However, the evolution of feathers (from reptiles to birds) and hairs (from reptiles to mammals) are independent events and their follicular structures result from convergent evolution. Because feathers do not have the anatomical equivalent of a hair follicle bulge, we are interested in determining where their stem cells are localized. By applying long-term label retention, transplantation and DiI tracing to map stem cell activities, here we show that feather follicles contain slow-cycling long-term label-retaining cells (LRCs), transient amplifying cells and differentiating keratinocytes. Each population, located in anatomically distinct regions, undergoes dynamic homeostasis during the feather cycle. In the growing follicle, LRCs are enriched in a 'collar bulge' niche. In the moulting follicle, LRCs shift to populate a papillar ectoderm niche near the dermal papilla. On transplantation, LRCs show multipotentiality. In a three-dimensional view, LRCs are configured as a ring that is horizontally placed in radially symmetric feathers but tilted in bilaterally symmetric feathers. The changing topology of stem cell activities may contribute to the construction of complex feather forms.     

Physiological Study of Stenotrophomonas maltophilia DHHJ in Feather Biodegradation:Structural Remodeling of Cell Surface and Dynamic Change in Kerastinase Activity

Poultry industry produces a vast amount of feather waste annually, which forms a burden for environment protection.However, feathers are valuable bio-resources with high keratinaceous protein content and can be converted into more valuable materials through some approaches such as biodegradation by microorganism-derived keratinases. The characters of keratinases in microorganisms remain largely undetermined. In this study,it is reported that the morphological change of cell surface and the activities of intracellular and extracellular keratinases in Stenotrophomonas maltophilia( S. maltophilia) DHHJ. S. maltophilia DHHJ was cultured on lysogeny broth( LB) and feather broth(FB) through fermenter technology,and ultrastructure of cell and keratinase activity including extracellular and intracellular enzyme were observed respectively. Ultrastructural change on the cell surface was only observed for the bacteria cultured on FB medium,but not on LB,suggesting that the change could be induced by feather keratin. Therefore, the results showed that extracellular keratinase is a kind of induction enzyme while intracellular keratinase is a kind of constitute enzyme in S. maltophilia DHHJ.     

Moulting tail feathers in a juvenile oviraptorisaur

Xu et al. describe the extraordinarily preserved feathers from two subadults of the oviraptorisaur Similicaudipteryx from the Yixian Formation of Liaoning, China. The preserved tail feathers of the juvenile specimen (STM4.1) show a morphology not previously observed in any fossil feathers. The tail feathers of an older, immature specimen (STM22-6) show a typical closed pennaceous structure with a prominent, planar vane. I propose that the feathers of the tail of the juvenile specimen are not a specialized feather generation, but fossilized 'pin feathers' or developing feather germs.     

A novel protease from yeast with specificity towards paired basic residues

Paired basic residues have been observed as sites of proteolytic processing of prohormones in a wide range of eukaryotic species. This strongly suggests that proteases exhibiting specificity towards paired basic residues may be involved in prohormone processing, but candidate enzymes have not so far been identified. Yeast Saccharomyces cerevisiae alpha-cells synthesize and secrete alpha-mating factor, a peptide of 13 amino acids, the processing of which from a larger precursor involves cleavage at paired basic residues (-Lys-Arg-). We have therefore used them as a simple model system for the study of prohormone processing and report here the identification, in cell lysates, of a novel protease which specifically recognizes and cleaves the peptide bonds between consecutive basic residues. The purified enzyme, which we have called propheromone -convertase Y, has a molecular weight (MW) of around 43,000. It cleaves various peptide substrates at paired basic residues, but not at single basic residues, implying it is distinct from trypsin-like proteases. Its unique substrate specificity suggests the enzyme may be involved in propheromone processing in vivo.     

基于PsbA-trnH,RbcL和trnL-F序列的野生葡萄系统发育

采用PCR技术从湘西地区的3种野生葡萄中分离PsbA-trnH、RbcL和trnL-F基因片段,克隆至pMD18-T载体中测序,结合GenBank/EMBL/DDBJ中公布的其他葡萄科植物相应cpDNA基因信息,使用Mega4构建系统发育进化树,分析其系统发育关系.结果显示,PsbA-trnH,RbcL和trnL-F这3种cpDNA基因序列均能用于葡萄科属间的分子鉴定,但结果与传统形态学分类存在一些差异,RbcL能用于葡萄属内种间的分子鉴定.     

一种基于改进随机游走的肺结节分割方法

传统的肺结节分割方法无法精确分割出肺结节外部毛刺,并且无法分离出与血管和胸壁相连的肺结节.针对这些问题,提出一种改进的随机游走算法并应用于肺结节的分割中.首先,根据Dirichlet边界条件计算得到的未标记点到标记点的概率值的大小将图像分为目标区域,背景区域和不确定区域,应用欧式距离计算不确定区域中节点与标记点的灰度差异并根据距离的大小将其进行分类.其次,提出了一种两点间抛物线法用于对初始分割结果进行二次分割.实验结果表明,与传统方法相比,所提方法实现了肺结节的精确分割,提高了计算机辅助诊断对肺结节进行分析和鉴别的精度.