基于mtDNA Cytb基因的马可·波罗盘羊遗传多样性与起源进化分析

为进一步明确马可·波罗盘羊(Ovis ammon polii)与家养绵羊的遗传进化关系,本试验提取20只马可·波罗盘羊的基因组DNA,并对其线粒体DNA(mtDNA)细胞色素b(Cytb)基因进行PCR扩增,下载GenBank中野生绵羊和家养绵羊的mtDNA Cytb基因序列,利用邻接法(Neighbor-Joining, NJ)构建系统发育树,以阐明野生绵羊和家养绵羊遗传多样水平与起源进化关系。结果显示,马可·波罗盘羊mtDNA Cytb基因全长1 140 bp,富含A、T碱基,含量为58.3%,存在10个单倍型,平均单倍型多样性(Hd)为0.884;存在122个SNPs位点,占核苷酸总数的2.35%,其中单一多态位点2个,简约信息位点120个,均为两碱基突变,转换发生的频率远远高于颠换;平均核苷酸多样性(pi)为0.02090;平均核苷酸差异性(K)为23.826,表明马可·波罗盘羊mtDNA Cytb区单倍型和核苷酸遗传多样性丰富。系统发育分析显示,野生绵羊分为明显的三支,其中马可·波罗盘羊单独形成一支,且与盘羊西藏亚种遗传距离最近,与天山盘羊、蒙古盘羊遗传距离最远,而家养绵羊与摩弗仑羊亲缘关系较近,与盘羊亲缘关系较远。以上结果表明盘羊对家养绵羊起源进化贡献较低,支持摩弗仑羊可能是家养绵羊野生祖先的观点。     

崇仁麻鸡mtDNA D-loop区遗传结构与遗传多样性分析

为研究崇仁麻鸡线粒体DNA(mitochondrial DNA,mtDNA)D-loop区遗传多样性和遗传结构，试验采用PCR产物直接测序的方法，测定崇仁麻mtDNA D-loop区的全序列，并与其他5个红色原鸡亚种进行系统进化关系分析。结果显示：30个样本的mtDNA D-loop区序列长度范围为1 231～1 232 bp，共发现27个多态位点，单倍型多样性（Hd）、核苷酸多样性（Pi）和平均核苷酸差异（K）数值分别为0.947、0.006 89和8.476。群体中16种单倍型划分为A、B、C和E单倍型类群。研究表明，崇仁麻鸡具有较高的线粒体遗传多样性，可能来源于不同的母系。     

安宁果下马线粒体DNA D-loop序列的初步分析

为了解安宁果下马线粒体DNA(mtDNA)的序列特点,试验采用普通马mtDNA序列设计PCR引物,对4匹安宁果下马的mtDNA D-loop区进行扩增的方法,得到mtDNA D-loop区的全序列。结果表明:4匹马mtDNA D-loop区的平均核苷酸变异率为2.67%,核苷酸变异位点较多,变异类型包括颠换、转换、插入、缺失4种形式,其中转换最普遍;检测到重复序列(GTGCACCT)的数量为24个,不同于其他马种。4匹安宁果下马个体间mtDNA D-loop区差异较大,表明其mtDNA D-loop区丰富的多态性。     

溧阳鸡线粒体DNA D-loop区遗传多样性研究

为了研究溧阳鸡线粒体DNA(mtDNA)D-loop区遗传多样性,试验采用PCR产物直接测序法对30只溧阳鸡mtDNA的D-loop区序列进行分析。结果表明:溧阳鸡549 bp D-loop区序列的T、C、A、G平均含量分别为30.0%、29.9%、27.1%、13.0%,共检测到19个突变位点,其中单一多态位点3个,简约多态位点16个;序列的核苷酸多样性为0.007 63,单倍型多样性为0.662;共获得7种单倍型,其中Hap单倍型占56.7%,群体内遗传距离为0.008。结合NJ系统发生树发现,溧阳鸡存在3个分支,揭示溧阳鸡在遗传组成上具有3个母系来源。     

兰州大尾羊mtDNA D-loop和Cytb区序列分析与多态性研究

利用mtDNA序列分析技术对20只兰州大尾羊遗传多态性进行分析,兰州大尾羊mtDNA D-loop区序列长度为1 210 bp,碱基组成分析发现,A、T、G、C碱基含量分别为29.0%、32.3%、23.5%、15.2%,其中A＋T为61.3%,G＋C为38.7%,G＋C含量明显低于A＋T。通过对兰州大尾羊线粒体DNA D-loop区的碱基突变和同源性比较分析得出兰州大尾羊D-loop区核苷酸多样度（Nucleotide diversity）Pi为0.037 85,7只兰州大尾羊来自3个不同母本。兰州大尾羊mtDNA Cytb区序列长度为1 580 bp,其中A、T、G、C碱基含量分别为27.2%、33.7%、26.7%、12.4%;A＋T为60.9%,G＋C为39.1%,G＋C含量明显低于A＋T。应用计算机软件DNAsp4.10进行单倍型分析,17个兰州大尾羊个体mtDNA Cytb区序列共发现了12个单倍型（Haplotype）,其中第1号和第10号、第2号和第5号共用一种单倍型,单倍型比例在兰州大尾羊群体中较高,遗传多态性较低。     

南阳牛mtDNA D-loop序列多态性分析

本文以3头南阳牛线粒体DNA D-loop区910bp的核苷酸序列进行了分析。结果发现，3头南阳牛D－loop区的核苷酸序列有3种单倍型。南阳牛1、2和3号D－loop区的平均核苷酸变异率分别为0.44%、4.84%和0.44%，其高变区的平均核苷酸变异率分别为0.81%、7.57%和0.00％。南阳牛1号的核苷酸变异类型只有转换一种式，南阳牛2号的核苷酸变异类型有转换、颠换、插入和缺失四种形式，南阳牛3号的核苷酸变异类型有转换和插入两种形式。在3头牛的核苷酸变异类型中，均以转换最常。说明南阳牛mtDNA D-loop区表现出丰富的核苷酸变异多态性。从线粒体D－loop区核苷酸序列的3种单倍型分析，提出南阳牛可能有两种不同的母系起源。     

江淮水牛线粒体D-loop区和Cytb基因遗传多态性及系统发育分析

为研究安徽江淮水牛群体的分子种质特性,本试验测定了江淮水牛2个亚群共82个个体的线粒体D-loop区和细胞色素b基因完整序列,分析了序列遗传多态性及系统进化关系,并结合GenBank中已发表的141条中国水牛D-loop序列,进行了联合分析。结果在D-loop区内共发现核苷酸多态位点91个,组成104个单倍型,其中32个是在江淮水牛中新发现的单倍型。总体mtDNA D-loop区核苷酸多样性为(0.015 43±0.001 42),单倍型多样性为(0.948±0.009)。其中,江淮水牛的mtDNA D-loop区核苷酸多样性为(0.014 89±0.002 32),单倍型多样性为(0.955±0.013),表明其群体遗传多样性丰富,群体变异性水平与中国其他水牛群体接近。根据线粒体D-loop区单倍型构建系统树和进化网络,显示江淮水牛存在沼泽型水牛线粒体支系A和B,表明其具有2个线粒体母系来源,其中B支又分为b1和b2两个亚支;针对细胞色素b基因的进化分析也支持这一结论。这些研究结果为今后开展江淮水牛遗传资源的保护和利用提供了客观依据。     

略阳乌鸡线粒体DNA控制区(D-loop)的遗传多样性分析

为了研究略阳乌鸡线粒体DNA控制区（mtDNA D-loop）的遗传多样性和起源,本研究对30只略阳乌鸡样品的mtDNA D-loop全序列进行了PCR扩增和测序,结合GenBank中公布的其他鸡的D-loop区序列,分析略阳乌鸡线粒体多态性及其起源。结果表明,略阳乌鸡mtDNA D-loop区全序列中,A、C、G、T平均含量分别为26.6%、26.6%、13.4%和33.4%,26个核苷酸多态位点均为转换位点,核苷酸多样度（Pi）为0.00705,单倍型变异度（Hd）为1.000,中性检验Tajima's D值为-0.47272。通过群体构建的系统进化树发现,略阳乌鸡样品在系统进化树上聚为4大分支。研究结果表明,略阳乌鸡群体内个体序列变异程度较大,遗传多样性丰富,揭示略阳乌鸡在遗传组成上具有4个母系来源。     

泰国红色原鸡和中国红色原鸡mtDNA控制区遗传多态性和分类关系研究

对泰国红色原鸡Gallus gallus gallus亚种和中国红色原鸡Gallus gallus spadiceus亚种各16个个体mtDNAD-loop序列进行系统分析,测定线粒体D-loop部分序列大小约为560bp,A、C、G、T这4种核苷酸的平均比例分别为13.6%、43.2%、4.3%和38.9%,A+T含量高于G+C含量。结果共发现27个变异位点,颠换和转换之比为0.13,没有观测到插入/缺失情况。测定的6种单倍型中,2个红色原鸡亚种没有共享单倍型,单倍型多样度分别为0.250和0.695,平均核苷酸差异数分别为3.750和10.833,核苷酸多样度分别为0.954%和2.757%。泰国红色原鸡中性检验的Tajima'sD值为-1.800(P<0.05),不符合中性突变。2个红色原鸡亚种间核苷酸分歧度(Dxy)为2.847%,核苷酸净遗传距离(Da)为0.991%。序列群体间的方差组分(Va)占总变异的47.31%,Fst=0.473,差异极显著(P<0.01);群体间mtDNAD-loopFst值也差异显著(P=0.035)。红色原鸡2个亚种具有不同的群体遗传结构,群体之间存在明显的遗传分化,本研究支持这2个亚种并非是同一个亚种的观点。     

庆阳驴mtDNA D-loop区遗传多样性及起源分析

【目的】研究庆阳驴养殖群体的遗传多样性与母系起源,了解其遗传信息,为保护庆阳驴种质资源、选育和遗传改良工作提供理论依据。【方法】随机选取133头庆阳驴,对其线粒体DNA(mitochondrial DNA,mtDNA)D-loop区序列进行PCR扩增、测序及比对,并探讨庆阳驴的遗传多样性与母系起源。【结果】在获得的520 bp D-loop碱基序列中,AT含量(57.3%)高于GC含量(42.8%),表现出碱基的偏倚性;检测到38个变异位点,包含8个碱基对的转换;其核苷酸多样性(Pi)、单倍型多样性(Hd)、平均核苷酸差异(K)分别为0.01591、0.895和8.274,与欧洲家驴和中国家驴研究的平均值相比较低,说明该驴品种核苷酸变异较为贫乏。庆阳驴mtDNA D-loop区存在35个单倍型,单倍型之间的遗传距离为0.002～0.042。系统进化结果显示,庆阳驴存在2个线粒体支系,表明其具有2个母系起源,且遗传距离表明,庆阳驴与克罗地亚家驴之间的遗传距离较近。【结论】本研究从分子水平初步揭示庆阳驴核苷酸变异比较贫乏,杂交程度高,mtDNA遗传多态性正逐步丧失,应加强庆阳驴品种的遗传资...     

4种鼢鼠线粒体DNA D-loop区全序列分析

采用PCR测序技术对采自甘肃境内的4种鼢鼠22个个体的线粒体DAND-loop区全序列进行了测定。结果表明：鼢鼠线粒体DNAD-loop序列长度为893、894、895、896或899bp,核苷酸位点突变类型有5种,即转换、颠换、插入、缺失及转换与颠换共存。碱基转换以T〈=〉C形式为主。其中T、C、A、G4种核苷酸的平均比例分别为34．1％、24．3％、30．1％、11．5％,A＋T含量（64．2％）明显高于G＋C含量（35．8％）。这4种鼢鼠22条线粒体DNAD-loop区发现20种单倍型,单倍型比例为81．82％,说明中国鼢鼠mtDNA遗传多态性很丰富。从系统发育树分析,4种鼢鼠明显聚为两类,推测鼢鼠可能有两个起源。     

中国9个家驴品种mtDNA D-loop部分序列分析与系统进化研究

本研究利用Dnasp4.10软件对中国9个家驴品种162个个体的mtDNA D-loop区385bp进行遗传多样性分析,共检测到32种单倍型35个核苷酸多态位点,其单倍型多样度为0.8137～0.9722,核苷酸多样度为0.0182～0.0270,表明我国家驴的遗传多态性丰富;利用MEGA3.1软件采用邻接法与3个努比亚野驴、3个索马里野驴和6个亚洲野驴的序列构建NJ系统发育树,并进行系统进化分析。结果表明:我国家驴的母系起源是非洲野驴中的努比亚野驴和索马里野驴,亚洲野驴不是中国家驴的母系祖先。     

固原鸡线粒体DNA控制区全序列测定及分析

固原鸡是宁夏唯一的地方鸡品种资源,具有肉质细嫩、味道鲜美、营养丰富等遗传特性。该试验采用PCR和直接测序的方法测定固原鸡(白羽、麻羽、红羽)线粒体DNA(mtDNA)控制区(D-loop)全序列,结果表明固原鸡3个类群线粒体DNA控制区全序列长度分别为1230bp、1231bp或1232bp。分析种内的遗传变异,3个类群固原鸡共发现6个变异位点,其中4个转换,2个缺失/插入,没有观测到颠换;A、T碱基含量占59.9%~60.0%,G、C碱基含量占40.0%;固原鸡与其它8种禽类的D-loop基因序列同源性的分子进化树聚类结果表明固原鸡不同类群与红色原鸡亲缘关系最近。     

麋鹿mtDNA控制区序列遗传多样性分析

为研究北京南海子麋鹿苑麋鹿的遗传多样性和进化系统,采用聚合酶链式反应(PCR)技术对13头麋鹿mtDNA控制区(D-环区)进行全序列扩增,对所得PCR产物进行测序,获得1 199 bp核甘酸序列片段,G+C含量占39.1%,其中仅有6个位点存在变异和转化,3种单倍型多样性为0.295,核苷酸多样性为0.039%。证明麋鹿的遗传多样性较低。将所测的麋鹿样本的mtDNA控制区序列与马鹿、坡鹿等鹿亚科动物进行比较,构建NJ分子系统发育树,研究其种间亲缘关系最近的为坡鹿、泽鹿。     

中国荷斯坦牛mtDNA D-Loop全序列分析

本文分析了3头中国荷斯坦牛线粒体DNA D－Loop区910bp核革酸序列的变异情况，结果发现，3头中国荷斯坦牛mtDNA D-Loop区的平均核苷酸变异率为0.59%，其核苷酸变异类型包括转换、颠换和插入3种形式，其中，以转换最为常见。     

关中驴线粒体DNA D-loop多态性分析

本文对 6头关中驴线粒体DNAD loop区 399bp的核苷酸序列进行了分析。结果发现 ,关中驴的D loop区核苷酸变异只有转换 1种形式。 6头关中驴D loop区的核苷酸序列组成 3种单倍型 ,单倍型比例为 5 0 .0 0 % ,说明关中驴mtDNA遗传多样性正逐步丧失 ,需要加强驴种质资源保护。以欧洲驴D loop序列为对照 ,关中驴 3种单倍型的核苷酸变异率分别为 4 .2 1%、4 .5 1%和 0 .2 5 %。在获得的 399bpD loop碱基序列中 ,共检测出核苷酸多态位点18个 ,多态位点比例为 4 .5 1%。从D loop区核苷酸序列的 3种单倍型分析 ,发现关中驴可能有 2种不同的母系起源     

Genetic Diversity of Mitochondrial DNA D-loop Sequences in Huili Black Goat

To explore the genetic diversity and origin for genetic resource protection of Huili Black goat, the mitochondrial DNA (mtDNA) D-loop was investigated. mtDNA D-loop sequences of 41 goats were analyzed by PCR, sequencing techniques, and biological information and the phylogenetic trees were constructed. The mtDNA sequences of the Huili Black goat ranged from 1211 to 1213 bp, and 2 sequences were 1211 bp, 29 sequences 1212 bp, and 10 sequences 1213 bp. The content of A+T (60.1%) was higher than one of G+C (39.9%). There were 9 haplotypes, and the haplotype diversity was 0.842+0.00368. The nucleotide diversity was 0.01542+0.00034. The phylogenetic analysis showed that Huili Black goat was distributed in a branch, and were closed to Jianchang Black goat, Chengdu Ma goat, Jintang Black goat, Guizhou White goat, Guizhou Black goat, but they were less related to Capra falconeri. Huili Black goats had rather abundant genetic diversity, and were greatly affected by other goat breeds in history.     

Analyses of Genetic Diversity and Phylogeny of mtDNA D-loop from Yak in Karakoram-Pamir Area

This experiment was conducted to clarify the genetic diversity,genetic differentiation and phylogenetic status of yak in Karakoram-Pamir area.The mtDNA D-loop region sequence was selected as a molecular marker,and the sequence and genetic diversity of the mtDNA D-loop region of yak in Karakoram-Pamir area were analyzed by PCR direct sequencing and bioinformatics methods.The yak sequence in GenBank was used.The maximum likelihood method was used to construct the phylogenetic tree and the intermediary network relationship.The results showed that the mtDNA D-loop sequence of yak in Karakoram-Pamir area was rich in A and T bases,with AT content of 61.2%,and there were 63 polymorphic loci,accounting for 7.04% of the total number of nucleotides.The results indicated that A and T bases were rich in the mtDNA D-loop sequences at 61.2%.There were 63 mutation sites,accounting for 7.04% of all nucleotides,The average haplotype diversity (Hd) was 0.806,the average nucleotide diversity (π) was 0.01528,and the average nucleotide difference (K) was 13.509,indicating that the yak was rich in genetic diversity in Karakoram-Pamir area;Through phylogenetic analysis,there were two branches in yak in China,forming two branches and six small clades.The yak in Karakoram-Pamir area involved in this study had two different maternal origins.Additionally,yak in the Karakoram-Pamir area was less shared with other breeds of yak haplotypes.In the branch C,the yak group in the Karakoram-Pamir area accounts for a large proportion and was shared with wild yak.The yak population in Karakoram-Pamir area had a unique genetic background,which might be the result of early domestication of wild yaks.It was suggested to increase the identification of yak breeds and the formulation of breed standards in this area,and strengthen the protection of yak genetic resources in this area.According to the current situation of the population,wild blood yaks were introduced for purification and rejuvenation to prevent breed degeneration and decrease of genetic diversity.The introduction of foreign yak breeds and disorderly hybridization were reduced to ensure the characteristics of this breed of high-quality yak breed resources.     

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.     

建昌马mtDNA D-loop区遗传多样性及系统进化分析

试验旨在以线粒体DNA(mitochondrial DNA,mtDNA)为切入点,研究建昌马的母系遗传多样性与系统进化。从建昌马(n=39)血液中提取基因组DNA,用PCR方法扩增mtDNA D-loop区并直接测序,分析其高变区247 bp序列信息,统计mtDNA D-loop区的单倍型及变异位点,计算单倍型多样性(haplotype diversity,Hd)、核苷酸多样性(nucleotide diversity,Pi)和平均核苷酸变异数(average number of nucleotide differences,K)。构建包括建昌马在内的19个品种马的NJ系统进化树,计算各品种间的遗传距离。结果显示,试验获得了清晰的PCR扩增产物,并通过直接测序方法获得了约1200 bp的序列。39匹建昌马mtDNA D-loop区247 bp序列(其中1个样品缺失1 bp)的AT碱基含量为61.45%,属AT碱基对富集区,检测到33个多态性位点,共显示26种单倍型,其中4种为共享单倍型,且Hap7和Hap1为优势单倍型,单倍型多样性为0.947,核苷酸多样性为0.02399,平均核苷酸变异数为5.901,显示丰富的母系遗传多样性;NJ系统进化树显示,建昌马分布在A、C、D、E、F、G共6个支系中,约50%的样品分布在A支系,显示出复杂的母系起源;建昌马与关中马的遗传距离最小(0.021),其次是三河马、文山马、韩国车巨马(0.024),与韩国济州岛马遗传距离最大(0.032)。本研究结果表明,建昌马的mtDNA D-loop高变区遗传多样性丰富,具有多个母系起源,且A支系占有明显优势,与关中马、文山马可能有共同的母系起源。