Sequence Analysis of Mitochondrial DNA D-loop Region in Xinjiang Goose

[Objective] The sequences of mitochondrial DNA D-loop region of Xinjiang Goose with three different colors of plumage were analyzed in order to study the genetic diversity of Xinjiang Goose, as well as the phylogeny and evolution. [Method] Ten geese were selected randomly from the core populations of grey-, mosaic- and white-plumaged Xinjiang Goose respectively with a total number of thirty as experi- mental materials, of which the blood samples were collected from the largest vein under the wing （brachial vein） for DNA extraction. Sequences of mitochondrial DNA D-loop regions were determined using DNA sequencing technology to analyze the polymorphism. In addition, the genetic distances among different populations were estimated through the comparison with the reference sequences. [Resull] The con- tents of A, G, C and T nucleotides in the D-loop region of Xinjiang Goose were 28.85%, 17.05%, 25.38% and 28.72%, respectively. The average haplotype diversity and nucleotide diversity of Xinjiang Goose were 0.583 and 0.056. Xinjiang Goose and Greylag Goose were clustered into the same group. [Conclusion] The results showed that Xinjiang Geese with three different colors of plumage all descend from Greylag Goose （Anser anser）.

Mutations in the D-loop region of mitochondrial DNA in gastric cancer

Objective: To investigate the mutati ons in the D-loop region of mitochondrial DNA (mtDNA) in gastric cancer. Methods: The mtDNA of D-loop region was amplified by PCR and sequence d in 20 samples from gastric cancer tissue and adjacent normal membrane. Results: There were 7/20(35%) mutations in the mtDNA of D-loop regio n in gastric cancer patients. There were four microsatellite instabilities among the 18 mutations. Nine new polymorphisms were identified in 20 patients. Conclusion: The mtDNA of D-loop region might be highly polymorphoric and the mutation rate is high in patients with gastric cancer.

Structure of Mitochondrial DNA Control Region of Pholis fangi and Its Phylogenetic Implication

In this study, the entire mitochondrial DNA(mtDNA) control region(CR) of Pholis fangi was amplified via polymerase chain reaction followed by direct sequencing. The length of the mtDNA CR consensus sequence of P. fangi was 853 bp in length. In accordance with the recognition sites as were previously reported in fish species, the mtDNA CR sequence of P. fangi can be divided into 3 domains, i.e., the extended terminal associated sequence(ETAS), the central conserved sequence block(CSB), and the CSB domain. In addition, the following structures were identified in the mtDNA CR sequence of P. fangi: 2 ETASs in the ETAS domain(TAS and cTAS), 6 CSBs in the central CSB domain(CSB-F to CSB-A), and 3 CSBs in the CSB domain(CSB-1 to CSB-3). These demonstrated that the structure of the mtDNA CR of P. fangi was substantially different from those of most other fish species. The mtDNA CR sequence of P. fangi contained one conserved region from 656 bp to 815 bp. Similar to most other fish species, P. fangi has no tandem repeat sequences in its mtDNA CR sequence. Phylogenetic analysis based on the complete mtDNA CR sequences showed that there were no genetic differences within P. fangi populations of the same geographical origin and between P. fangi populations of different geographical origins.

Population Genetic Analysis of Sillago nigrofasciata (Perciformes:Sillaginidae) Along the Coast of China by Sequencing Mitochondrial DNA Control Region

Sillago nigrofasciata, a small to moderate size nearshore species, is newly found along the eastern and southern coasts of China. The present study is carried out in order to analyze the population genetics of the S. nigrofasciata. The control region sequence of mitochondrial DNA revealing 73 haplotypes were obtained from 162 individuals collected at 8 locations along the coast of China. The whole S. nigrofasciata population along the coast of China showed a low nucleotide diversity(0.012) and a high population diversity(haplotype diversity)(0.943), and all the 8 local populations showed low nucleotide diversities(0.014 – 0.001), suggesting the protective measures are effective. The haplotypes of the 8 local populations were widely distributed in haplotype network diagram and neighbor-joining phylogenetic tree, while no branch associating with sampling locations was detected. Recent gene flow analysis showed asymmetric gene exchanges among local populations. The pairwise FST values and unweighted pair-group method with arithmetic mean(UPGMA) tree revealed a certain amount of genetic difference among local populations. Moreover, analysis of molecular variance(AMOVA) reflected genetic differences between hypothetical subdivision groups. Neutral test and mismatch distribution of pairwise nucleotide suggested S. nigrofasciata may have experienced recent population expansion events. The historical geographic events associating with ice age may be the main explanation to the heterogeneity among local populations with short geographic distances, and the homogeneity among local populations with long geographic distances.

A Molecular Phylogeny of Macaca Based on Mitochondrial Control Region Sequences

Nucleotide sequences of segments of the mitochondrial control regions were analyzed to infer the phylogenetic relationships among 7 macaques.High nucleotide diversity in Macaca assamensis and relatively low diversity in M.thibetana were found.Based on the ML tree from control regions,species in our study can roughly be sorted into three species groups except for the phylogenetic position of M.fascicularis,i.e.,silenus group,including M.leonina;sinica group,including M.arctoides,M.assamensis,and M.thibetana;and fascicularis group,including M.mulatta and M.cyclopis.A discrepancy between earlier studies (Fooden & Lanyon,1989;Tosi et al,2003a;Deinard & Smith,2001;Evans et al,1999;Hayasaka et al,1996;Morales & Melnick,1998),our result supported the hypothesis that M.fascicularis diverged earlier than M.leonina.Mitochondrial paraphyly in eastern M.mulatta (with respect to M.cyclopis) and eastern M.assamensis (with respect to M.thibetana) were clearly observed in our study.In accordance with the results of Y chromosome,allozyme,nuclear genes and some morphological data (Delson,1980;Fooden & Lanyon,1989;Fooden,1990;Tosi et al,2000,2003a,b;Deinard & Smith,2001),our study on control region sequences supported M.arctoides to be classified into the sinica group.However,this result disagreed with the previous mtDNA studies (Hayasaka et al,1996;Morales & Melnick,1998;Tosi et al,2003a).

A genetic diversity comparison between captive individuals and wild individuals of Elliot’s Pheasant (Syrmaticus ellioti) using mitochondrial DNA

Maintaining genetic diversity is a major issue in conservation biology. In this study, we demonstrate the differences of genetic diversity levels between wild and captive individuals of Elliot’s Pheasant Syrmaticus ellioti. Wild individuals showed a higher genetic diversity level than that of the captive individuals. Nucleotide diversity and haplotype diversity of wild individuals were 0.00628 and 0.993, while those of captive individuals were 0.00150 and 0.584 respectively. Only 3 haplotypes of mtDNA control region sequence were identified among 36 captive individuals, while 16 unique haplotypes were identified among the 17 wild individuals in this study. One captive haplotype was shared by a wild individual from Anhui Province. It is concluded that a low number of founders was the likely reason for the lower level genetic diversity of the captive group. Careful genetic man- agement is suggested for captive populations, particularly of such an endangered species, to maintain genetic variability levels.

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1231~1232 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、0.00689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。

Genetic variation of the small yellow croaker(Larimichthys polyactis)inferred from mitochondrial DNA provides novel insight into the fluctuation of resources

The small yellow croaker(Larimichthys polyactis)belongs to the family Sciaenidae,which is an offshore warm fish species and widely distributed in the western Pacific.In this study,the variation of genetic diversity and genetic differentiation among L.polyactis populations was analyzed by mitochondrial DNA control region.A total of 110 polymorphic sites were checked,which defined 134 haplotypes.High level of haplotype diversity(h=0.993±0.002)was detected in the examined range.Population genetic structure analyse(analysis of molecular variance,Fst)showed there were high gene flow among L.polyactis populations.The result showed that there were relatively high genetic diversity and low genetic differentiation among the Yellow Sea and the East China Sea populations,which can be attributed to diverse habitats,wide distribution range and high mutation rate of control region.Using phylogenetic methods,coalescent analyses(neutrality tests,mismatch distribution analysis,Bayesian skyline analyses)and molecular dating interpreted in conjunction with paleoclimatic and physiographic evidence,we inferred that the genetic make-up of extant populations of L.polyactis was shaped by Pleistocene environmental impacts on the historical demography of this species.Besides,relatively constant genetic diversity and larger effective population size were detected in recent L.polyactis population.The result showed that the fishing policy certainly,such as the summer closed fishing,played a role in protecting resources of L.polyactis.This study can offer a wealth of biological novelties which indicates genetic structure of L.polyactis population and provides the foundation for resources protection and policy setting.

The Genetic Structure and Diversity of Repomucenus curvicornis Inhabiting Liaoning Coast Based on Mitochondrial COⅠ Gene and Control Region

[Object] This study was conducted to explore the genetic diversity and structure of the wild Repomucenus curvicornis inhabiting Liaoning Coast, China. [Method] The mitochondrial COⅠ gene and control region（CR） were PCR amplified from the wild R. curvicornis populations from the Liaodong Bay（n=22） and the northern Yellow Sea（n=18）, sequenced and analyzed for genetic diversity. [Result] The contents of A, T, C and G of 624 bp COⅠ gene were 24.09%, 31.04%, 25.28%, and 19.59%, and those of 460 bp CR fragment were 32.96%, 32.80%, 14.86% and 19.38%, respectively. The total number of variable sites, average number of nucleotide differences（ k）, haplotype diversity（H） and nucleotide diversity（π） based on COⅠ gene were 38, 4.67,（0.96±0.02） and（0.007 5±0.004 2）, and those based on CR fragment were 26, 3.35,（0.97 ±0.02） and（0.007 3±0.004 3）, respectively. Based on mitochondrial COⅠ gene and CR, the genetic diversity of Liaodong Bay population was lower than that of the northern Yellow Sea population. The AMOVA analysis based on CR fragments revealed almost significant genetic divergence between the Liaodong Bay and the northern Yellow Sea populations, while there was no significant genetic divergence based on COⅠ gene. The results showed that CR and COⅠ gene are effective molecular markers for detecting the genetic diversity of R. curvicornis population, while CR is more reliable than COⅠ gene in detecting the genetic structure. [Conclusion] CR is an appropriate marker for genetic analysis of marine fish population.

西藏牦牛mtDNA D-loop区的遗传多样性及其遗传分化

通过测定和分析西藏11个牦牛类群114个个体的mtDNA D-loop区全序列,对西藏牦牛的遗传多样性、类群间的亲缘关系及其遗传分化进行了研究。结果表明:①西藏牦牛mtDNA D-loop区全序列长度为890—896 bp,4种核苷酸T、C、A、G的平均比例分别为28.5%、25.3%、32.4%、13.8%,西藏牦牛mtDNA D-loop区富含碱基A+T,表现出一定的碱基偏好性。②共检测到130个变异位点,占分析总位点数的14.33%;其中单一多态位点85个,占多态位点总数的65.38%,简约信息位点45个,占多态位点总数的34.62%。序列变异中碱基缺失、插入和碱基替换等均有,其中碱基替换变异类型中转换114次,颠换12次,在转换变异类型中以A/G、T/C为主,占95.61%,在颠换变异类型中以A/T为主,占75%。③在114个个体中鉴定出90种单倍型,单倍型多样性为0.981±0.008,核苷酸多样性为0.01056±0.00701,均说明西藏牦牛具有丰富的单倍型类型。④90种单倍型分为2个聚类簇(Ⅰ、Ⅱ),聚类簇Ⅰ包含80种单倍型,占全部单倍型的88.89%,涵盖本研究中所有的西藏牦牛类群;聚类簇Ⅱ中有10种单倍型,占单倍型总数的11.11%,涉及的类群有工布江达、帕里、丁青、巴青、江达、类乌齐、桑桑、桑日、斯布,说明西藏牦牛可能有2个母系起源。⑤西藏牦牛类群间核苷酸分歧度(Dxy)在0.503%—1.416%之间,聚类分析和AMOVA分析显示西藏牦牛可分为两大类,康布牦牛、嘉黎牦牛为一类,其余的牦牛类群为另一类。

野牦牛(Bos grunniens mutus)mtDNA D-Loop区的遗传多样性

为从分子水平上评价野牦牛(Bosgrunniens mutus)的遗传多样性,对6头野牦公牛线粒体DNAD-loop区全序列进行了克隆和测定(GenBank登录号为:FJ548840～FJ548845),结合GenBank中已刊登的2条野牦牛的相应序列,使用BioEdit7.0.9、DnaSP4.10.1、Arlequin3.11等生物信息学软件,对全部8条序列开展了比对分析,确定了多态位点与单倍型数目,计算了核苷酸多样度和单倍型多样度。结果表明8条野牦牛线粒体DNAD-loop区全序列长度在891～894bp之间,其中A、T、G和C4种核苷酸的平均含量分别为32.68%、28.65%、13.46%和25.21%,A+T的平均含量为61.33%。排除4处核苷酸的插入或缺失后,共检测到39处转换和颠换位点,占分析序列总长度的4.38%,其中包括4处单一多态位点和35处简约信息位点。依据序列间核苷酸变异共确定了7种单倍型,单倍型多样度(h)为0.9643,核苷酸多样度(π)为0.02144,提示野牦牛群体具有丰富的遗传多样性。

舟山小黄鱼线粒体DNA D-loop区序列变异的遗传多样性分析

小黄鱼（Pseudosciaena polyactis）为我国重要海产经济鱼类之一, 过度捕捞和环境污染等因素造成其资源日益衰退。研究小黄鱼种群遗传结构对其资源的保护及其可持续利用有十分重要的意义。该研究采用聚合酶链式反应（PCR）技术对浙江舟山附近海域小黄鱼种群53个个体的mtDNA D-loop区全序列进行扩增, 序列长度在795-801bp 之间, 长度差异不大。采用Clustal X1.83、MEGA3.1、DnaSP4.0等生物信息学软件进行遗传多样性分析, 结果显示：53条小黄鱼线粒体DNA D-loop 区的T、C、A 和G 碱基平均含量分别为30.3%、23.1%、32.3%和14.3%, 排除13 处核苷酸的插入或缺失后, 共检测到93处转换和颠换位点, 约占分析序列总长度的11.6%, 其中包括53 个单一多态位点和40 个简约信息位点, 共确定了52 种单倍型, 单倍型多样性（hd）为0.9993, 单倍型间的平均遗传距离为0.012, 转换/颠换平均值为4.305, 平均核苷酸差异数（k）为9.73875, 核苷酸多样性（π）为0.01233,表明舟山小黄鱼遗传多样性处于中等水平。

基于线粒体DNAD-loop区部分序列分析舟山海域带鱼种群遗传结构

带鱼（Trichiurus lepturus Linnaeus）,俗称刀鱼、白带鱼,隶属鲈形目（Perciformes）,带鱼科（Trichiuridae）,带鱼属（Trichiurus）,广泛分布于世界各温热带海域,在我国主要分布在东海、南海、黄海和渤海[1]。带鱼为我国最重要的捕捞对象,其产量多年来一直位居我国海洋捕捞鱼类产量的首位,占有十分重要的渔业经济地位。舟山带鱼是全国首批海鲜类地理标志证明商标海鲜,曾与大黄鱼、小黄鱼、墨鱼并称为我国＂四大渔业＂。自20世纪70年代后,由于受过度捕捞和环境变化等影响,舟山海域的带鱼资源出现了严重衰退;

基于线粒体DNAD-loop区全序列分析藏鸡遗传多样性及其起源进化关系的研究

通过对藏鸡线粒体DNA（mt DNA）Dloop区全序列的测序和比对,结合Gen Bank已经测出Dloop区全序列的部分品种鸡的序列,探讨藏鸡的遗传多样性和母系起源。结果表明,藏鸡DNA（mt DNA）Dloop区全长1 231-1 232 bp、1 231 bp单倍型在859 bp处存在C碱基缺失。在20只个体中,共发现20处单核苷酸多态位点,7种单倍型。系统发育分析发现,藏鸡7种单倍型可以分为A、B、E三个分支。A分支与红色原鸡（Gallus gallus murghi）聚为一类,推测可能起源于红色原鸡的印度亚种分支,B和E与红色原鸡滇南亚种（Gallus gallus spadiceus）聚为一类,推测这两个分支可能起源于云南、缅甸附近地区的红色原鸡滇南亚种。研究从分子水平上为藏鸡的遗传资源保护和开发利用提供参考。

陕西省林麝mtDNA D-loop区序列结构和种群遗传多样性

林麝(Moschus berezovskii)曾广泛分布于中国,由于盗猎和栖息地缩小,秦岭地区野生种群数量迅速下降,圈养繁殖种群已成立了几十年,但大多数圈养种群的遗传背景不清,种群规模增长非常缓慢。为了给这一物种的保护和管理提供有用的信息,调查了陕西省林麝1个圈养种群3个野生种群线粒体DNA(mt DNA)D-Loop 632 bp片段的遗传多样性和种群结构。在69个个体中其碱基组成为A+T的平均含量63.2%高于G+C含量36.8%,共检测到变异位点171个(约占总位点数的27.05%)。核苷酸多样性(Pi)为0.04424,平均核苷酸差异数(K)为19.908。69个个体分属32个单倍型,单倍型间的平均遗传距离(P)为0.070。32个单倍型构建的NJ系统树聚为3个分支,4个林麝群体中的单倍型是随机分布的。4个群体的平均遗传距离为0.043(标准误SE为0.005),凤县养殖场群体与留坝和陇县群体的亲缘关系较远。单倍型间的平均遗传距离为0.043,可见其遗传分化尚未达到种群分化的水平。结果表明,陕西省林麝群体mt DNA D-loop区序列存在着较丰富的变异和遗传多样性,凤县野生群体和凤县养殖场群体的核苷酸多样性和单倍型多样较高,养殖场种群没有出现近亲繁殖及遗传多样性下降的情况。凤县野生群体和凤县养殖场群体两者遗传分化较小,存在着较高的基因流水平。

中国荷斯坦牛和鲁西黄牛mtDNA D-loop序列多态性分析

为了从母系遗传角度深入阐明中国荷斯坦牛和鲁西黄牛的群体遗传多样性以及起源进化,本研究采用PCR测序法测定了9头中国荷斯坦牛和11头鲁西黄牛的线粒体DNAD-loop区的部分序列,并经剪切后进行生物信息学软件分析。结果表明,20个个体D-loop区共711bp,共检测到19种单倍型和50个多态位点。核苷酸多样性(Pi)为0.02133±0.00454,单倍型多样性(Hd)为0.994±0.019,平均核苷酸差异数(k)为15.14620。构建的NJ网络进化树共分为两大支系,其中部分鲁西黄牛与瘤牛聚为一支,而中国荷斯坦牛和部分鲁西黄牛与普通黄牛聚为一支。说明中国荷斯坦牛和鲁西黄牛群体遗传多样性均较高;鲁西黄牛同时含有瘤牛和普通黄牛的血统,而中国荷斯坦牛只含有普通黄牛的血统。

中国蒙古马与国外纯血马mtDNA D-Loop高变区序列比较

比较分析了4匹中国蒙古马和4匹国外纯血马的线立体DNA(mtDNA)D Loop高变区400bp核苷酸序列的变异情况。结果发现,4匹中国蒙古马mtDNAD Loop高变区的平均核苷酸变异率为3 69%,而纯血马的为4 00%,其核苷酸变异类型均包括转换、颠换和缺失3种形式,其中以转换最为常见。核苷酸变异基因座多,并且存在长度变异,不同变异在个体之间差异也很大,因此说明中国蒙古马和国外纯血马的mtDNAD Loop高变区都具有丰富的多态性。

藏獒线粒体DNA D-loop区序列测定及其分类地位研究

根据家犬线粒体基因组DNA序列设计引物,获得了藏獒(Tibetan mastiff)线粒体DNA D-loop区全序列,并以灰狼、郊狼作为外类群对藏獒、家犬亚种内6个大型家犬品种进行了系统发育分析。试验结果发现:藏獒线粒体DNA D-loop区序列全长1250 bp,与家犬源序列的同源性为96.06%,其中有20个碱基缺失;系统发育分析发现藏獒、家犬亚种内6个大型家犬品种与灰狼聚为一大类,而郊狼自成一类,说明藏獒与其他家犬品种一样起源于灰狼,是家犬亚种内的一个品种,在分类地位上隶属于食肉目、犬科、犬属、狼种、家犬亚种;在家犬亚种内,藏獒与英国牧羊犬、兰伯格犬聚为一类,而德国牧羊犬与瑞典猎鹿犬、黑俄罗斯更犬聚在一起,再与圣伯纳犬聚为一类,从分子水平上验证了英国牧羊犬等大型犬可能含有藏獒血统的观点。

清远麻鸡mtDNA D-loop区遗传多样性分析

研究旨在通过线粒体DNA(mitochondrial DNA,mtDNA)D-loop区分子标记研究清远麻鸡的遗传多样性。试验通过PCR扩增和直接测序的方法对80只清远麻鸡的线粒体DNA D-loop区的全序列进行检测,并与红色原鸡进行系统进化分析。研究结果表明:清远麻鸡mtDNA D-loop区序列长度在1231~1232 bp之间,单倍型多样性、核苷酸多样性和平均核苷酸差异分别为0.861、0.00606和7.456。80条序列共发现30个多态位点,定义了18种单倍型,归属可分为A、B、C、D和E 5个单倍型类群。清远麻鸡在mtDNA水平上具有很高的遗传多样性,有多个母系来源。研究结果为清远麻鸡种质资源遗传评估、有效保种和选育利用提供了理论依据。

急性白血病骨髓细胞线粒体DNA D-loop区的突变检测

本研究旨在检测急性白血病(AL)患者骨髓细胞线粒体DNA(mtDNA)D-loop区突变和线粒体微卫星不稳(mtMSI),并分析它们与AL发病的关系。选取19例初诊的AL患者,提取骨髓细胞mtDNA并对mtDNA D-loop区序列行PCR扩增,通过正反向直接测序对PCR扩增产物基因序列进行检测,并将测序结果与修订的剑桥标准序列(revised Cambridge reference sequence,rCRS)和有关数据库(MITOMAP数据库、GenBank数据库、mtDB数据库)进行比对。结果表明:AL的mtDNA D-loop区突变率达79%(15/19例),在D-loop区发现215个变异位点(35个突变位点、180个SNP位点)和1个mtMSI;发现1个新的突变类型nt150 C-CT,同时发现不同年龄、不同AL分型(AML,B-ALL)的患者间突变个数无统计学差异(P>0.05)。结论:AL的骨髓细胞mtDNA D-loop区存在高频率突变,且其突变可能与AL发病有关。