The primary flight feathers, secondary flight feathers, tail feathers and down feathers of Grus nigricollis and Grus grus were microscopically imaged, and the morphological data were determined and compared by statistical analysis. The quantitative indexes of morphological structure were statistically analyzed by single factor analysis and sample t test, and the Fisher discriminant function of characteristic indexes was established. The results were showed as following: the length of the barb in the inner web of remiges feathers, the angle between the barb in the inner web of tail feathers and the area of the accessory pinna of a primary flight feather, are remarkably different between G. nigricollis and G. grus in the terms of macrostructure; the number of cilia couples and ventral teeth from distal barbules in secondary flight feathers, the number of ventral teeth in proximal barbules of remiges feathers, the number of hamuli from distal barbules in tail feathers, the distance between nodular and diameters of nodular between the 2 kinds of Grus in the terms of microstructure also showed significantly different;macroscopic and microscopic characteristics of the Grus feathers were quantitatively analyzed, and Fisher discriminant function based on the difference index was constructed. The accuracy rate of using back substitution method to test the discriminant equation is 80.2%. It suggested that Grus of primary and secondary flight feathers and tail feathers of sample classification can be achieved by the number of hamuli, cilia couples, ventral teeth from distal barbules, the number of ventral teeth in proximal barbules, the angle between the barb in the inner web, the length of the barb in the inner web of remiges feathers, the area of the accessory pinna and Length of a feather shaft. It further enriches the identification methods or approaches of rare crane species in China.

为了解禽流感病毒(AIV)在野禽和家禽之间的传播特点,本研究于2020年3月～2021年3月在野生鸟类资源丰富的拉市海国际高原湿地采集到野鸟粪便样品1367份、家禽泄殖腔拭子420份和环境水样20份,共计1807份样品,通过鸡胚接种和RT-PCR分离鉴定出1株斑头雁来源的H9N2 AIV和2株家禽来源的H9N2 AIV.利用Illumina Miseq测序平台获得3株分离病毒的全基因组序列,并构建了其遗传进化树,分析了与流感病毒的传播能力及致病力相关的关键氨基酸位点的特征.遗传进化分析结果显示,野禽源和家禽源AIV具有相同的遗传进化特征:3株H9N2 AIV均属于欧亚谱系h9.4.2.5分支的病毒,其HA、NA基因为Y280-like亚群,PB2、M基因为G1-like亚群,PB1、PA、NP和NS基因为F/98-like亚群,推测3株分离株均为重组病毒,重组模式为中国流行的H9N2 AIV S基因型.氨基酸位点分析结果显示,3株分离病毒HA、NA、PB2、PB1、M1和NS1蛋白的突变位点均与病毒跨种属传播能力和小鼠致病力增强相关;同时野禽源H9N2 AIV同样存在家禽源分离株相似的HA蛋白N166D替换和NA蛋白颈部aa63～aa65位点缺失,但PA蛋白中未发生N383D突变.以上结果表明,本研究中野禽源H9N2 AIV可能源于家禽的传播,病毒在自然宿主野禽中发生了适应性突变.本研究首次对拉市海高原湿地野禽源与家禽源H9N2 AIV的遗传变异特征进行了系统分析,为禽流感的综合防控提供基础数据.

禽腺病毒4型(FAdV-4)是引起心包积液-肝炎综合征(HPS-IBH)的主要病原,主要危害鸡、鸭、鹅等家禽并造成家禽行业严重的经济损失.随着HPS-IBH疫病严重程度的增加,家禽间的传染性也急剧升高,国内外加强对该病的研究及防治.论文阐述了FAdV-4病毒粒子主要结构蛋白六邻体(Hexon)、五邻体(Penton)和纤突(Fiber),以及主要结构蛋白在病毒感染中的不同功能.近年来国内暴发的FAdV-4的基因组序列分析特征表明毒株与印度株同源性极高,并且新毒株存在ORF19缺失.还总结了针对FAdV-4的特异性LAMP、ELISA等病毒检测技术和预防FAdV-4的基因工程疫苗和亚单位疫苗,阐述了FAdV-4的病原学特征,可为综合防控HPS-IBH提供参考.

为了解H5N2亚型禽流感病毒(Avian influenza virus,AIV)的血凝素蛋白(Hemag-glutinin,HA)系统进化特征,借助NCBI influenza virus resource数据库,下载禽源A型流感病毒(Influenza A Virus,IAV)H5N2亚型HA核酸序列,分析毒株的宿主、分离时间等特征,并构建HA蛋白的遗传进化树,分析其系统发生.结果显示:NCBI数据库收录的H5N2 AIV的HA核酸序列1 272条,序列在NCBI发布时间集中于2005-2007年、2011年、2014-2016年;582条序列为野禽来源,宿主主要分布于雁形目、鸡形目和鹆形目的野禽.系统发生分析结果表明:H5N2 AIV的HA蛋白可聚类为亚欧谱系及北美谱系两大分支,前者可分为三个亚系,后者可分为两个亚系.研究结果呈现了H5N2 AIV HA基因在时间及空间上的进化特征,为H5N2 AIV引起的疫病预警和防控提供理论基础.

Objective:To study the effect of different immune doses in rabbit anti-enterovirus 71 (EV71) serum preparation on the antibody titer.Methods:Three doses of 5, 50 and 100 μg were selected in this experiment. There were 3 groups of 3 rabbits in each group.After the mixture of EV71 inactivated vaccine and Freund’s adjuvant, the rabbits in the three groups were immunized by intramuscular injection. The rabbits were immunized once at 0, 7, 14 and 28 d, respectively. Blood samples were collected every 7 d, serum was separated and neutralizing antibody titer was detected.Results:The antibody titer of 100 μg was significantly higher than that of 5 μg ( t=-3.282) and 50 μg ( t=-2.486), on day 42 ( P<0.05). There was a linear relationship between the titer of rabbit serum antibody and the immune dose (within the range of 5-100 μg). The linear model was established and the regression equation y=478.229 x-2 041.820 was obtained. Conclusion:Among the 3 immune doses selected in this experiment, the titer of serum antibody increases with the increase of immune dose, and shows a linear relationship.