黑龙江东部地区猪瘟病毒分子流行病学研究

本研究参考公开发表的Alfort株基因组全序列 ,用计算机软件Dnastar的PrimerSelect程序设计了两对SCFVE2基因高变区的特异性引物 ,对黑龙江东部地区分离的 5株猪瘟野毒 (HL、JN、MSND、MSPD和MSHT株 )进行RT_PCR扩增、克隆和序列测定 ,并将这 5株野毒的高变区基因序列与国内外公开发表的参考毒株的相应部分进行了比较。结果表明 ,5株分离毒均为基因II群 ,且形成两个独立的分支 ,HL、JN株与HCLV株氨基酸差异在 60 %以上 ,而MS株与HCLV株氨基酸差异在 3 0 %左右。

人兽共患羊传染性脓疱病疑似疫情的病原鉴定及其致病性分析

为确定呼和浩特市某规模化羊场发生的一起人兽共患羊口疮(orf)疑似疫情的病原,本研究从采自病羊和疑似感染人员的皮肤病损组织中成功分离到病毒,通过电镜观察、PCR和间接免疫荧光试验确诊为羊口疮病毒(ORFV)。对该分离株的B2L、ORFV121基因进行克隆测序,并与其他ORFV毒株进行遗传相关性分析,同时对采自1例病羊的样品进行病理组织学观察,最后采用兔体感染模型对此次人源分离株和羊源分离株的致病性进行分析。结果显示,本研究所涉规模羊场发生的人兽共患羊口疮疑似疫情确为orf田间野毒株引发,且感染致病力较强。患病羊除了嘴唇、口鼻部等处皮肤组织表现结痂、脓疱和花椰菜样等常见病症外,部分患病羊的外阴、乳房、蹄甲边缘皮肤组织出现增生、皲裂和结痂病变,且有些患病羊的消化道(如瘤胃、网胃)黏膜组织也出现溃疡和丘疹样病灶。测序分析显示,本研究中羊源、人源2个分离株的B2L和ORFV121基因不存在差异,表明它们来自于同一ORFV毒株的感染,且与疫苗株ORFV D1701的亲缘关系较近。兔体感染试验证实该毒株毒力较强(TCID_(50)为10^(5.0)/m L)。

Analysis on the Origin and Phylogenetic Status of Tong Sheep Using 12 Blood Protein and Nonprotein Markers

This study is based on the Tong sheep obtained by the random sampling method of typical colonies in the central area of Baishui County in Shaanxi Province, China. An investigation was undertaken to clarify the gene constitution of blood protein and nonprotein types of Tong sheep. Twelve genetic markers were examined by starch-gel electrophoresis and cellulose acetate electrophoresis. Polymorphism in Tong sheep was found at the following 10 loci, transferrin （Tf）, alkaline phosphatase （Alp）, leucine aminopeptidase （Lap）, arylesterase （Ary-Es）, hemoglobin-β （Hb-β）, X-protein （X-p）, carbonic anhydrase （CA）, catalase （Cat）, malate dehydrogenase （MDH）, and lysine （Ly）, whereas, albumin （A1） and postalbumin （Po） loci were monomorphic. Genetic approach degree method and phylogenetic relationship clustering method were used to judge the origin and phylogenetic status of Tong sheep. Results from both methods maintained that Tong sheep belonged to the ＂Mongolia group＂, and Mongolia sheep was the origin of Tong sheep. This was also supported by the history of Tong sheep breeding. Compared to the phylogenetic relationship clustering method, the genetic approach degree method was more reliable for the extraction from East and South of Central Asia, and was more effective in reflecting the breeding course of Tong sheep.

Analysis of Genetic Relationship of 64 Local Varieties of Morus atropurpurea Roxb.in Guangdong Based on ISSR Marker

[Objective] The study aimed at analyzing the genetic relationship of 64 local varieties of Morus atropurpurea Roxb.from the Pearl River Basin in Guangdong and Guangxi Provinces.[Method] Genetic diversity of 64 local varieties of Morus atropurpurea Roxb.was analyzed by ISSR molecular marker technique.The genetic relationship among these local varieties was researched by UPGMA method based on the genetic similarity coefficient.[Result] 128 bands were amplified from the total DNA of 64 local varieties using 13 ISSR primers,of which 109 bands accounting for 85.15% were polymorphic.It meant that there was rich genetic diversity among the local varieties tested.The genetic similarity coefficients among 64 local varieties were relatively high with a range of 0.500 0-0.929 7.In addition,64 local varieties were divided into two categories and the second could be further divided into 10 subcategories.It was suggested that the genetic relationship of 64 local varieties of Morus atropurpurea Roxb.based on ISSR marker analysis has a certain correlation with geographical distribution.[Conclusion] ISSR marker technology was suitable for evaluating genetic relationship and genetic diversity of local varieties of Morus atropurpurea Roxb.in Pearl River Basin,and could provide scientific basis for DNA fingerprinting and identification of varieties of Morus atropurpurea Roxb.

Inheritance Pattern of Microsatellite Loci and Their Use for Kinship Analysis in the Japanese Scallop Patinopecten yessoensis

The inheritance mode of seven microsatellite markers was investigated in Patinopecten yessoensis larvae from four con-trolled crosses,and the feasibility of using these markers for kinship estimation was also examined. All the seven microsatellite loci were compatible with Mendelian inheritance. Neither sex-linked barriers to transmission nor major barriers to fertilization between gametes from the parents were evident. Two of the seven loci showed the presence of null alleles in two families,suggesting the need to conduct comprehensive species-specific inheritance studies for microsatellite loci used in population genetic studies. However,even if the null allele heterozygotes were considered as homozygotes in the calculation of genetic distance,offspring from four families were all unambiguously discriminated in the neighbor-joining dendrogram. This result indicates that the microsatellite markers used may be capable of discriminating between related and unrelated scallop larvae in the absence of pedigree information,and of investigating the effective number of parents contributing to the hatchery population of the Japanese scallop.

Genetic Relationship Analysis of Ramie Accessions by RAPD Markers

Genetic relationship of 12 ramie varieties with different drought resistance was analysed by using RAPD.Twenty-five 10-mer random primers were used to amplify the total DMA of these varieties.The results showed that the amplified products of 12 ramie varieties could be obtained with 12 primers.The length of amplified products was 0.6-5.15 kb.Ninety bands were identified in total,of which 11 bands were common in all 12 varieties and 79 bands were polymorphic.The polymorphic bands were 87.78% of the total amplified bands.According to the result of cluster analysis,12 ramie varieties could be divided into two classes and three groups.It was found that high drought resistant varieties were clustered into different groups or subgroups in the same class,which shows near relationship among them.