玉树牦牛与四个牦牛群体线粒体DNA D-Loop区遗传多样性分析

利用线粒体DNA标记方法从分子水平上研究牦牛的遗传多样性。根据牦牛线粒体DNA(mtDNA)序列设计引物,扩增出长度为1 000 bp左右的片段,序列对比分析。结果表明:mtDNA D-Loop区长度为945 bp,共发现变异位点127个,单倍型71个,单倍型多样度(Hd)为0.909±0.016,核苷酸多样性(pi)为0.082;其中玉树牦牛发现变异位点74个,单倍型27个,单倍型多样度(Hd)为0.885±0.034,核苷酸多样性(pi)为0.0134;申扎牦牛单倍型多样度、核苷酸多样性和平均核苷酸差异数均最高;5个牦牛群体D-Loop区序列具有一定的A/T碱基偏好性。玉树牦牛不遵循中性进化(P0.05),其余4个牦牛群体符合中性进化(P0.05);玉树牦牛与类乌齐牦牛和帕里牦牛的遗传距离较近(0.023、0.018),申扎牦牛与斯布牦牛的遗传距离最远(0.533)。发现玉树牦牛与其余4个群体的牦牛在同一个分支。斯布牦牛和申扎牦牛群体出现两个分支,说明玉树牦牛在进化的过程中可能不存在相互交流的情况。     

甘南牦牛线粒体DNA?Cytb基因序列分析

为深入研究线粒体DNA Cytb基因对牦牛在低氧环境适应性中的作用,本研究克隆获得甘南牦牛线粒体DNA Cytb基因全序列,并对其理化性质进行分析。获得甘南牦牛线粒体DNA Cytb基因全序列1 140 bp,编码379个氨基酸,编码产物分子质量98.5 KD,理论等电点为4.98,是亲水性的稳定蛋白,存在明显的碱基AT使用倾向性,该序列在哺乳动物中具有很高的保守性。     

全、半血野牦牛与家牦牛杂交试验

本试验通过人工授精技术,采用野牦牛颗粒冻精与家牦牛进行全、半血杂交方式,经后代生长发育观测,杂一代野血牛犊体尺、体重、剪毛量均高于本交家牦牛犊,尤以体重差异明显,全血野血牛犊体重比家牦牛犊增重3.4kg,增重率25.1%,体重差异极显著(P<0.01),半血野血牛犊体重比家牦牛增犊重2.1kg,增重率15.6%,体重差异极显著(P<0.01),野牦牛与家牦牛杂交优势明显。     

藏绵羊线粒体DNA遗传多样性研究

本文用ＡｐａＩ,ＡｖａⅡ,ＢａｍＨＩ,ＢｃｌⅡ,ＣｌａＩ,ＥｃｏＲⅤ,ＨｉｎｄⅢ,ＨｐａＩ,ＫｐｎＩ,ＰｓｔＩ,ＰｖｕⅡ,ＸｂａＩ,ＸｈｏＩ等１４种内切酶,分析了１２头藏绵羊ｍｔＤＮＡ的限制性片断长度多态性,共检测了３５个酶切位点,发现ＡｖａⅡ,ＣｌａＩ,ＰｖｕⅡ三种酶切类型具有多态性,根据不同个体的ｍｔＤＮＡ的酶切类型,发现藏绵羊存在三种ｍｔＤＮＡ单倍型,计算ｍｔＤＮＡ多态度π值为０．００１２,     

野牦牛冻精与家牦牛杂交改良试验

随机选用生产性能好、健康无疾病成年母牛160头,组建每群为80头的试验群和对照群,测定犊牛初生、6月龄体重和体尺。试验结果表明,在同等饲养管理条件下,试验群和对照群受胎率差异不显著,初生犊牛、6月龄犊牛试验群比对照群生产性能差异极显著。因此,利用野牦牛复壮家牦牛是加快牦牛选育和提高生产性能最有效的途径。     

中国地方猪种线粒体基因组遗传多样性及其系统发育分析

为从分子水平上探究中国地方猪种遗传多样性和分类地位,本试验采用生物信息学方法比较了6个类型共22个中国地方猪种的线粒体基因组全序列,分析了其多态性,并构建了6个类型猪种线粒体D-loop区单倍型的网络中介图以及基于线粒体D-loop序列、Cytb基因、完整编码区序列的系统进化树。结果表明,6个类型22个猪种中共检测到了144个多态位点,22种单倍型,说明地方猪种具有丰富的遗传多样性;地方猪线粒体基因组序列中核苷酸变异以转换为主,且Ti/Tv大于转换/颠换比临界值（2.0）,变异位点均符合中性突变。6个类型猪种间遗传距离均较小,且有共享单倍型。系统进化树结果表明,6种类型地方猪种主要聚为两个支系。表明线粒体D-loop序列及Cytb基因均可作为研究种内系统发育、起源进化的分子标记。     

肃南县牦牛导入青海大通牛场野牦牛血液复壮效果调查

[目的]通过引进野血种公牦牛改良当地牦牛可有效遏止牦牛退化,进一步巩固和改善我县牦牛品种质量,恢复其原有的优良生产性能和品种特征,提高经济效益.[方法]本文以野牦牛和家牦牛杂交后代与家牦牛后代为研究对象,分别测定了杂种牦牛和家牦牛的初生、6月龄、18月龄体尺、体重.[结果]显示,在同等条件下,1/4野血牦牛初生、6月龄、18月龄体尺、体重均显著高于同龄家牦牛,经t检验差异极显著（P＜0.01）.[结论]用野血牦牛改良家牦牛,是目前更新复壮家牦牛群体的有效途径之一,能获得很强的杂种优势,对提高经济效益,增加农牧民收入,保护生态环境都具有十分重要的意义.     

四川黄牛品种线粒体DNA 遗传多样性研究

测定了四川黄牛5个品种的线粒体细胞色素b部分片段（420bp）42个个体以及28个个体线粒体DNA控制区（D-loop）的全序列，结合已报道的中国8个黄牛品种22个个体的线粒体DNA控制区（D-loop）全序列，分析结果表明：四川黄牛的部分Cytb基因片段有5个变异位点，7种单倍型可分为以2个单倍型为主的2大类型；线粒体DNA控制区检测到64个变异位点，28种单倍型，单倍型H1～H23为普通黄牛类型，单倍型H24～H28为瘤牛类型的单倍型。在四川黄牛中，67．86％为普通牛类型，32．14％为瘤牛类型。研究结果表明四川黄牛主要有2类母系来源。     

西藏阿里地区牦牛生态类群分子遗传多样性研究

利用多种分子标记鉴定西藏阿里牦牛生态类群遗传多样性状态,以期为阿里牦牛遗传资源的保护、开发和利用奠定理论基础.利用13个微卫星标记位点及线粒体D-Loop高变区分别对69头和50头西藏阿里牦牛进行了遗传多样性评估.结果显示,在13个微卫星位点中共检测出124个等位基因,其中TGL122和ILSTSO50位点的复等位基因...     

查吾拉牦牛线粒体全基因组序列及系统发育分析

为了解查吾拉牦牛（Bos grunniens）线粒体全基因组结构,对查吾拉牦牛线粒体基因组进行了PCR扩增并测序、组装及注释。结果表明,查吾拉牦牛完整的线粒体DNA为环状分子,全长16 323 bp,其核苷酸组成分别为：A占33.71%,T占27.30%,C占25.78%,G占13.21%,A+T含量为61.01%。总体组成包括22个tRNA基因,2个rRNA基因,13个蛋白编码基因（ND1～ND6、ND4L、COX1～COX3、ATP6、ATP8和CYTB）,以及1个非编码控制区（D-loop）。ND6和8个tRNA基因（tRNA-Ser、tRNA-Pro、t RNA-Glu、t RNA-Tyr、tRNA-Cys、tRNA-Asn、tRNA-Ala和tRNAGln）均编码在轻链上,其余基因编码在重链上。系统发育分析结果表明,查吾拉牦牛与娘亚牦牛亲缘关系较近。综上所述,查吾拉牦牛线粒体基因组全序列可用于进一步研究其起源进化和育种改良。     

基于Cytb基因部分序列分析巴州牦牛遗传多样性及其系统地位

对20头巴州牦牛Cytb基因部分序列550 bp进行分析,共发现7个变异位点,定义了4种单倍型;结合GenBank中bos属普通牛、瘤牛、牦牛、印度野牛和爪洼野牛5个近缘种以及沼泽水牛的Cytb基因同源区序列进行分析,以绵羊作为外群,分别采用邻接(NJ)法和最大简约(MP)法构建分子系统发育树,得到基本一致的拓扑结构。结果表明:推测巴州牦牛的系统地位在牛亚科中介于属与种之间,将其定义为bos属或者Poephagus属均有其一定的依据,但是本研究认为将其归属为bos属中的一个亚属可能更为合理,巴州牦牛可能具有2种母系起源。     

牦牛线粒体DNA D-loop区序列测定及其在牛亚科中分类地位的研究

根据普通牛线粒体DNA序列设计引物,获得了九龙牦牛线粒体D-loop区全序列,并以羊亚科绵羊属绵羊作为外类群利用D-loop区序列对牛亚科代表性物种（牦牛、野牦牛、普通牛、瘤牛、美洲野牛、欧洲野牛和亚洲水牛）进行了系统发育分析。结果发现：牦牛线粒体DNA D-loop区序列全长893 bp,与普通牛源序列的同源性为87.4%,其中有17个碱基的缺失;在牛亚科内,牦牛、野牦牛与美洲野牛（美洲野牛属）间的序列差异百分比最小,为6.2%～6.8%,而与牛属中普通牛、瘤牛间的序列差异百分比较大,为10.0%～11.3%;系统发育分析发现：牦牛、野牦牛首先与美洲野牛聚为一类,说明牦牛、野牦牛与美洲野牛属间的遗传相似性较高、亲缘关系较近,而与牛属间的遗传相似性较低、亲缘关系较远;结合古生物学、形态学、分子生物学的证据,支持将牦牛、野牦牛划分为牛亚科中一个独立属即牦牛属的观点。     

五指山猪线粒体控制区序列分析及遗传多样性研究

为了研究五指山猪遗传多样性和系统地位,本研究采用PCR产物直接测序法得到55条五指山猪线粒体控制区(mtDNA D-Loop)全序列,并结合GenBank中发表的1条五指山猪mtDNA D-Loop全序列进行结构分析、遗传多样性研究及系统发育分析。结果发现,56条序列中出现21次保守区变异,即"TTATAAAACAC"序列重复,共定义13个单倍型,发现14个变异位点,单倍型多样度(Hd)和核苷酸多样度(Pi)分别为0.838和0.00334,表明五指山猪遗传多样性较丰富。五指山猪线粒体控制区序列构建的系统发育树和Network网络分析呈现两大分支,推测有两个母系起源,且与GenBank中其他23个猪种的聚类结果表明,五指山猪与长江流域以南地区的猪种有着较近的亲缘关系。     

Complete Mitochondrial DNA D-Loop Sequence and Genetic Diversity of Wuzhishan Pig

In order to research the genetic diversity and phylogenies of Wuzhishan pig, 56 complete mtDNA D-Loop were analyzed.55 sequences were amplified by polymerase chain reaction (PCR) and 1 sequence was downloaded from GenBank.The results showed that repetitive sequence "TTATAAAACAC" appeared in the conservative regions of 21 mtDNA D-Loop sequences.13 haplotypes and 14 variable sites were observed in 56 sequences.Haplotype diversity and nucleotide diversity (Hd =0.838 and Pi=0.00334) indicated that Wuzhishan pig had high genetic diversity.Two branches in the phylogenetic tree and Network analysis diagram indicated that there were two maternal origins in Wuzhishan pig.The phylogenetic tree of Wuzhishan pig and other 23 species showed that Wuzhishan pig had close genetic relationship with the pig breeds in the south region of the Yangtze river.     

1／4野血牦牛,1／2野血牦牛及家牦牛初产产乳性能测定

对１／４野血牦牛、１／２野血牦牛和家牦牛的初产牛进行１２０天的产奶量和乳脂率测定。结果：日均挤乳量,１／４野血牦牛为０．９４±０．２２ｋｇ,１／２野血牦牛为１．０５±０．１８ｋｇ,家牦牛为０．１１±０．１０ｋｇ;乳脂率,１／４野血牦牛为６．２９％,１／２野血牦牛为５．６％,家牦牛为６．２４％。经ｑ检验,３组的日均挤乳量和１／４野血牦牛与家牦牛的乳脂率均差异不显著（Ｐ＞０．０５）,而１／２野血牦牛因野性较大,难以挤净含脂较高的二奶,以致乳脂率低于其它两组。     

Genetic Diversity and Phylogenetic Relationships of the Complete Mitochondrial Genome in Chinese Indigenous Pig Breeds

In order to explore the genetic diversity and the classification status of the Chinese domestic pigs at the molecular level, the complete mitochondrial DNA (mtDNA) genomic sequences of 22 Chinese indigenous pig breeds from 6 types were downloaded from GenBank for the analysis using the bioinformatics method. The polymorphism of nucleic acid sequences was analyzed,the molecular phylogenetic tree based on D-loop sequences, Cytb gene, complete coding region mtDNA sequences and the Median-Joining network of the mtDNA D-loop haplotypes were constructed for 22 pig breeds from 6 types. The results showed that a total of 144 mutation sites among 22 pig breeds were detected, 22 haplotypes were discovered, which indicated that Chinese indigenous pig breeds had abundant genetic diversity. According to the complete mtDNA genomic sequences analysis, which suggested that the main mutations was transition, the transition/transversion ratio was greater than 2.0 and all mutations were in line with the neutral mutation. Our findings clearly demonstrated that there was a near genetic distance among 6 types, meanwhile, the shared haplotypes were found. The phylogenetic tree showed that Chinese indigenous pigs from 6 types were diverged from two ancestors.The results indicated that mtDNA D-loop and Cytb gene might serve as molecular markers for phylogenesis, origin and evolution.     

A Genetic Diversity Analysis of Mitochondrial DNA D-loop Region in Four High Quality Chicken Breeds

This study was conducted to elucidate the genetic diversity of mitochondrial DNA (mtDNA) D-loop region in Qingyuan partridge chicken group 1,Qingyuan partridge chicken group 2,Yangshan chicken and Qingyuan Yellow feather black-bone chicken.The specific primers were designed according to mtDNA D-loop region of Gullus gullus spadiceus (accession No.:NC_007235.1) in GenBank.The sequence was analyzed after PCR amplification and sequencing,and the haplotype number,polymorphism number,haplotype diversity,nucleotide diversity and nucleotide mean difference were counted.The evolution divergence among breeds was calculated by Mega 5.10 software,and the phylogenetic tree was constructed.The results showed that the length of mtDNA D-loop region in four high quality chicken breeds was 591 bp,and 549 bp were used for subsequent analysis.The content of A,T,C and G were 27.2% to 27.3%,30.1% to 30.4%,29.5% to 29.8% and 12.8% to 12.9%,respectively,and the average content of G+C was 42.5%.There were 92 polymorphic sites which contained 14 singleton variable sites and 78 parsimony informative sites,and the percentage of transitions and transversions were 89.13% (82/92) and 10.87% (10/92),respectively.The haplotype diversity ranged from 0.682 to 0.835,and the nucleotide diversity ranged from 0.00849 to 0.01167.There were 32 haplotypes in all sequences,which could be divided into clades A,B,C and E,however,most of the individuals belonged to clades B (51.2%) and E (37.6%).The phylogenetic tree results showed that four high quality chicken breeds could be classified as 4 branches which were consistent with the haplotypes classification results.The results indicated that the four high quality chicken populations from Qingyuan had relatively high haplotype and nucleotide diversity and likely shared two or more common maternal lineages.     

西藏牦牛mtDNA ND6遗传多样性及系统进化分析

为从分子水平上探究西藏牦牛的序列多态性、遗传多态性及其系统进化关系,对西藏15个牦牛类群150个个体的mtDNA ND6基因全序列进行了测定,确定了多态位点和单倍型数目,计算了单倍型多样性(Hd)和核苷酸多样性(Pi),并构建了分子聚类关系图和单倍型系统发育树。结果表明:西藏牦牛mtDNA ND6基因全序列长度均为528bp,T、C、A和G 4种碱基的平均比例分别为42.2%、7.6%、20.9%、29.3%,存在一定的碱基组成偏倚性。序列变异中存在转换、颠换2种核苷酸变异类型,其中转换37次,颠换2次,表现出较强的转换偏倚性。根据序列间核苷酸变异共确定7种单倍型,其中Hap_1为西藏牦牛类群的主流单倍型,其余6种单倍型为部分类群所特有。平均单倍型多样性(Hd)、平均核苷酸多样性(Pi)分别为0.2978、0.00191,揭示西藏牦牛mtDNA ND6遗传多样性较贫乏。根据遗传距离构建了分子聚类关系图,表明西藏15个牦牛类群可分为2大类;根据7种单倍型序列构建了单倍型系统发育树,表明西藏牦牛存在2个母系起源。     

Analysis on Genetic Diversity and Phyletic Evolution of mtDNA Cytb Gene in Zhongdian Yak

In order to investigate the genetic diversity and the origin of evolutionary relationship of Zhongdian yak,we analyzed the complete sequence of 15 individuals Cytb gene,its sequence polymorphism was analyzed,and the phylogenetic tree was constructed.The results showed that the length of the nucleotide sequence were 1 140 bp,with nucleotide frequencies of 26.3%,31.8%,13.1% and 28.8% for T,A,G and C,respectively.Three haplotypes were identified of 15 individuals,with 3 polymorphic sites,including two conversions,one transversion,haplotype diversity was 0.2571 and nucleotide diversity was 0.00035.Phylogenetic analysis suggested that Zhongdian yak and Bos mutusc clustered firstly,then gathered with Bison bison,which indicated that there were high genetic similarity and closer genetic relationship,genetic similarity with other cattle genus was relatively low.Combining with the proof of molecular biology and paleontology,the result supported the point that Bos grunniens and Bos mutus were classified as an alone genus in Bovinae.