中国东北地区远东鼩鼱遗传多样性与遗传结构

对中国东北地区3个种群(大兴安岭、小兴安岭和长白山山脉)的远东鼩鼱(77个样本)Cyt b基因全序列进行分析,共获得64个单倍型。整体单倍型多态性为0.9920,核苷酸多态性为0.0105,表明该地区远东鼩鼱具有较高遗传多样性,且长白山山脉远东鼩鼱种群遗传多样性明显高于大兴安岭和小兴安岭种群。F-统计量、遗传相似系数和遗传距离分析结果均显示,种群间和采样地间的遗传距离与地理距离基本相符。方差分析显示,种群间的变异占总变异的33.4%,种群内的采样地间变异占总变异的10.2%,采样点内部变异占总变异的56.4%。种群历史分析显示,东北地区远东鼩鼱未经历过数量扩张。从GenBank下载了欧亚其他地区远东鼩鼱序列进行遗传结构研究。远东鼩鼱系统发生树分化为2大分支:一大支主要由大兴安岭和小兴安岭种群构成,两种群具有一定分化;另一大支又分为两个分支。中介网络图显示,远东鼩鼱具有3个谱系:一个谱系主要由大兴安岭和小兴安岭的单倍型样本构成,还包括长白山山脉的4个单倍型样本;另一谱系包括来自于中国东北地区3个种群的个别单倍型,还包括俄罗斯贝加尔湖单倍型和芬兰单倍型;最后一个谱系完全是由长白山山脉单倍型构成。遗传多样性、系统发生树和中介网络图结果均表明,长白山山脉为远东鼩鼱末次冰期避难所。     

陇东黄土高原石鸡的遗传多样性与保护

石鸡 (Alectorischukar)是我国北方重要的猎鸟 ,由于栖息地片断化和人类狩猎 ,陇东黄土高原上的石鸡数量正日益减少。本文用PCR直接测序的方法 ,测定了陇东黄土高原 8个石鸡种群mtDNA控制区I区和部分II区的4 91个碱基 ,探讨其遗传多样性。 78个样本共发现 2 4个变异位点 (占所测序列的 4 .89% )和 2 5种单倍型 (占所测样本的 32 .0 5 % )。 8个种群中 ,铜川种群的序列变异率、单倍型多样性和核苷酸多样性都最高 ,分别是 0 .4 7、0 .82和 0 .0 0 2 9;而红回种群的最低 ,仅分别为 0 .10、0 .2 8和 0 .0 0 0 8,这与红回种群受奠基者效应、遗传隔离和自然选择的作用有关。 8个种群共享 1种单倍型C1,说明它们来自共同祖先 ,是 1个单系群 ,属于 1个进化显著单元 ,但它们聚成两个集群。两集群间单倍型相似性指数仅 0 .15 ,遗传距离达 0 .4 3% ,单因素方差分析显示遗传变异差异显著 (F =5 .0 2 >F0 .0 5(14 ,1) =4 .0 6 ) ,分别有 13种和 10种单倍型为两个集群所特有。基于遗传差异性 ,陇东黄土高原的石鸡应分为两个管理单元进行保护 ,尤其对遗传变异和遗传多样性最高的铜川种群应进行重点保护。     

大石鸡兰州亚种的mtDNA种群遗传结构、单倍型分布和遗传多样性

大石鸡(Alectorismagna)是中国西北部的特有种。我们测定了大石鸡兰州亚种(A.m.lanzhouensis)8个地理种群106个样本的线粒体DNA控制区5′端458bp序列,研究其种群遗传结构和遗传多样性。27个变异位点共确定25种单倍型,其中单倍型M2广泛分布,而许多单倍型为一些地方种群特有。单倍型分布沿着南北方向变化,存在明显的地理结构。8个种群中核苷酸多样性最高的是定西种群,0.0069,最低的是海原种群,0.0028;单倍型多样性最高的是武山种群,0.86,最低的是北道种群,0.52。北方种群比南方种群具有更高的遗传多样性。系统发生树和单倍型分布表明,大石鸡兰州亚种存在两个明显的分支。溯祖理论、更新世冰期和花粉支持兰州亚种起源于兰州盆地,这个盆地是其遗传多样性的中心。     

澜沧江老挝纹胸鮡Cytb基因的序列变异与遗传结构分析

老挝纹胸鮡是分布于澜沧江流域的一种特有鱼类,喜激流底栖生活。为了解其各地理种群间的遗传结构与遗传变异,文章分析了129尾采自澜沧江8条支流水系的老挝纹胸鮡mtDNA细胞色素b基因1 138 bp的序列变异,共发现16个多态性位点,定义了15个单倍型。澜沧江老挝纹胸鮡遗传变异较低,平均单倍型多样性指数和核苷酸多样性指数分别是h=0.299,π=0.299,有3个种群甚至没有变异,分子变异方差分析结果表明各种群内变异大于各种群间变异,种群间没有差异。对老挝纹胸鮡所有种群进行的单倍型错配分布呈现单峰型,中性检验结果均为负值(Tajima’s D=?2.36965,P<0.02;Fu’s Fs=?20.975,P<0.05)表明,澜沧江老挝纹胸鮡自然种群可能经历过近期的种群扩张事件。     

黄山短尾猴mtDNA控制区序列变异及种群的遗传多样性

短尾猴属灵长目(Primates)猴科(Cercopithecidae)猕猴属(Macaca),是我国特有的国家二级保护动物。为了更有效地保护其野生种群,本文研究了黄山短尾猴种群内的遗传多样性,并对黄山短尾猴与四川短尾猴种群间的遗传差异进行了分析。共测定了黄山短尾猴7个群体中的30个样本的mtDNA控制区5′端493bp的序列,只发现了7个变异位点,定义了3种单倍型,单倍型序列之间缺乏变异,种群中的核苷酸多样性很低(0.006);3种单倍型相应地将黄山种群分为了3个亚群,不同亚群之间呈现出一定的片断化分布,从分子水平上初步揭示了短尾猴黄山种群的遗传多样性。与四川短尾猴的相应序列比较,黄山短尾猴控制区序列存在很大差异,共有59个变异位点,而且存在大片段的碱基插入/缺失,有78%的遗传变异发生在两个种群之间,两个种群间的核苷酸歧异度已达8.21%。进一步分析表明,黄山短尾猴与四川短尾猴之间存在着极显著的遗传分化(FST=0.399,P<0.001),基于最大似然法和邻接法构建的系统发生树均将两者聚为不同的类群,支持将它们归入各自的管理单元。     

云南洞密蛛的种群遗传结构初探

云南洞密蛛Trogloneta yunnanense（Song&Zhu, 1994）是生活在云贵高原的一种洞穴蜘蛛。本文基于6个洞穴种群159只个体样本的线粒体COⅠ基因,初步探讨了该物种的种群结构和遗传多样性特征。研究结果表明：1)159个样本共检测到16个单倍型,种群间无共享单倍型,遗传多样性呈现出总体高、种群内低、单倍型多样性高、核苷酸多样性低的模式;2)种群间遗传分化极显著,种群内变异小,种群间F_ST值均在0.9以上（P<0.01）,种群间基因流小（Nm=0.01）,种群间变异占总变异的95.75%,种群内变异仅占4.25%;3)中性检验和核苷酸错配分布检验显示,云南洞密蛛未经历种群扩张,群体大小保持稳定。推测洞穴隔离和地下极端环境条件可能维持着云南洞密蛛的种群规模稳定,同时促进其种群间的遗传分化。     

高原鼢鼠线粒体谱系地理学和遗传多样性

高原鼢鼠是一类地下独居啮齿动物,为青藏高原特有种之一。为研究该物种的谱系地理学和遗传多样性,本文测定了采自青藏高原东部3个地理种群8个小种群共37个个体的线粒体D-loop区序列变异。在长度为627bp的序列中,共发现50个变异位点,定义了26种单倍型。该物种的单倍型多样性（Haplotype diversity,H）较高和核苷酸多样性（Nucleotide diversity,πn）较低。谱系分析得到3个稳定的分支,分别与采集的地理种群相吻合：同一地理种群内单倍型之间遗传差异小,而不同地理来源的单倍型之间存在较大区别。距离隔离分析表明高原鼢鼠的遗传分化与地理距离呈正相关。AMOVA分析同样表明地理种群之间存在显著差异：地理种群间变异占遗传变异的80.45%。高原鼢鼠的这种遗传结构特点可能主要是由于第四纪气候变迁、该物种稳定的地下生活环境和有限的迁移能力造成的。     

基于COI和ND5序列的中国南部唇鱼骨和间鱼骨群体遗传结构

唇鱼骨和间鱼骨均为分布较广的初级淡水鱼类,是理想的亲缘地理研究材料;且两者形态特征较为相似,不易鉴别,故两者的分布记述和物种有效性存在争议.为了解我国南部唇鱼骨和间鱼骨的群体遗传结构并探讨两者的物种有效性,本研究对8条水系的唇鱼骨和9条水系的间鱼骨共130尾个体的COI和ND5基因序列片段进行了测定,并对这两个基因的组合序列(2151 bp)进行了分析.结果表明: 在130尾个体的COI和ND5基因组合序列中,共有196个核苷酸变异位点,共检测出50个单倍型,单倍型多样性为0.964,核苷酸多样性为0.019,遗传多样性较高.基于COI和ND5基因组合序列构建的 NJ 树显示,所有种群可分为两支,支系Ⅰ包含了韩江和九龙江的全部单倍型以及瓯江的部分单倍型,余下的单倍型组成了支系Ⅱ.两支系间的遗传距离为0.036,而唇鱼骨与间鱼骨之间的遗传距离为0.027.单倍型网络图表明,韩江、九龙江种群和其他水系种群分化较大;漠阳江种群由海南岛种群扩散而来;海南岛各种群及漠阳江种群的单倍型分支与珠江水系单倍型的分支之间的亲缘关系较近,与长江水系单倍型分支之间的亲缘关系则较远;湘江、桂江和柳江之间的亲缘关系较近.AMOVA分析结果显示,地理区之间的变异约占71.2%,地理区内种群间变异约占16.6%,种群内的变异占12.2%,表明其遗传分化主要来自地理区之间.错配分析及中性检验结果显示,全部种群、唇鱼骨种群、间鱼骨种群、支系Ⅰ和支系Ⅱ在历史上均没有发生过明显的扩张.     

基于COI和ND5序列的中国南部唇魚骨和间魚骨群体遗传结构

唇魚骨和间魚骨均为分布较广的初级淡水鱼类,是理想的亲缘地理研究材料;且两者形态特征较为相似,不易鉴别,故两者的分布记述和物种有效性存在争议.为了解我国南部唇魚骨和间魚骨的群体遗传结构并探讨两者的物种有效性,本研究对8条水系的唇魚骨和9条水系的间魚骨共130尾个体的COI和ND5基因序列片段进行了测定,并对这两个基因的组合序列(2151bp)进行了分析.结果表明:在130尾个体的COI和ND5基因组合序列中,共有196个核苷酸变异位点,共检测出50个单倍型,单倍型多样性为0.964,核苷酸多样性为0.019,遗传多样性较高.基于COI和ND5基因组合序列构建的NJ树显示,所有种群可分为两支,支系Ⅰ包含了韩江和九龙江的全部单倍型以及瓯江的部分单倍型,余下的单倍型组成了支系Ⅱ.两支系间的遗传距离为0.036,而唇魚骨与间魚骨之间的遗传距离为0.027.单倍型网络图表明,韩江、九龙江种群和其他水系种群分化较大;漠阳江种群由海南岛种群扩散而来;海南岛各种群及漠阳江种群的单倍型分支与珠江水系单倍型的分支之间的亲缘关系较近,与长江水系单倍型分支之间的亲缘关系则较远;湘江、桂江和柳江之间的亲缘关系较近.AMOVA分析结果显示,地理区之间的变异约占71.2%,地理区内种群间变异约占16.6%,种群内的变异占12.2%,表明其遗传分化主要来自地理区之间.错配分析及中性检验结果显示,全部种群、唇魚骨种群、间魚骨种群、支系Ⅰ和支系Ⅱ在历史上均没有发生过明显的扩张.     

基于COI和ND5序列的中国南部唇鱼骨和间鱼骨群体遗传结构

唇鱼骨和间鱼骨均为分布较广的初级淡水鱼类,是理想的亲缘地理研究材料;且两者形态特征较为相似,不易鉴别,故两者的分布记述和物种有效性存在争议.为了解我国南部唇鱼骨和间鱼骨的群体遗传结构并探讨两者的物种有效性,本研究对8条水系的唇鱼骨和9条水系的间鱼骨共130尾个体的COI和ND5基因序列片段进行了测定,并对这两个基因的组合序列(2151 bp)进行了分析.结果表明: 在130尾个体的COI和ND5基因组合序列中,共有196个核苷酸变异位点,共检测出50个单倍型,单倍型多样性为0.964,核苷酸多样性为0.019,遗传多样性较高.基于COI和ND5基因组合序列构建的 NJ 树显示,所有种群可分为两支,支系Ⅰ包含了韩江和九龙江的全部单倍型以及瓯江的部分单倍型,余下的单倍型组成了支系Ⅱ.两支系间的遗传距离为0.036,而唇鱼骨与间鱼骨之间的遗传距离为0.027.单倍型网络图表明,韩江、九龙江种群和其他水系种群分化较大;漠阳江种群由海南岛种群扩散而来;海南岛各种群及漠阳江种群的单倍型分支与珠江水系单倍型的分支之间的亲缘关系较近,与长江水系单倍型分支之间的亲缘关系则较远;湘江、桂江和柳江之间的亲缘关系较近.AMOVA分析结果显示,地理区之间的变异约占71.2%,地理区内种群间变异约占16.6%,种群内的变异占12.2%,表明其遗传分化主要来自地理区之间.错配分析及中性检验结果显示,全部种群、唇鱼骨种群、间鱼骨种群、支系Ⅰ和支系Ⅱ在历史上均没有发生过明显的扩张.     

江西井冈山国家级自然保护区蝶类资源研究

2002年至2008年对井冈山国家级自然保护区的蝴蝶种类进行调查,共发现有蝴蝶231种,隶属ll科128属,其中包括国家I级保护动物金斑喙凤蝶Teinopalpus aureus Mell。离斑带蛱蝶Athymaranga Moore、珠翠蛱蝶Euthaliaper MlaChouetWang、斜带缺尾蚬蝶Dodonaouida Moore和花裙陀弄蝶Thoressa submacula（Leech）这4种为江西省新记录,另有135种为保护区首次记载。井冈山国家级自然保护区蝴蝶区系成分以东洋界为主,占总种数的73．26％。     

井冈山自然保护区野生兰科植物资源分布及特点

通过对江西省井冈山自然保护区兰科(Orchidaceae)植物的调查,分析了保护区内兰科植物的物种多样性、区系特点、分布格局,并采用SPSS18.0软件对井冈山及其邻近保护区属的种类进行相关和聚类分析。结果表明:井冈山兰科植物种类丰富,共有兰科植物34属75种,中国特有兰科植物19种。井冈山兰科植物资源垂直分布格局明显,不同海拔段的兰科植物分布差异较大,中低海拔的物种分布较多,资源相对保存较好;区系成分复杂多样,井冈山兰科植物属的地理成分可以划分为10个类型2个变型,热带性属占优势,占总属数的67.3%,但热带分布的种仅占本地区总种数的37.3%,而温带分布的种却占62.7%,故井冈山自然保护区属热带植物区系与温带植物区系过渡的交汇地带。井冈山兰科植物与齐云山自然保护区的相似性最高,与武夷山自然保护区的相似性最低。     

江西井冈山地区沟谷季雨林及其超地带性特征

江西井冈山地区位于中国东部中亚热带地区南缘,属北半球湿润区。该地区地处罗霄山脉中段,地势高耸,沟谷深切,生境极富多样化,在其沟谷地区保存有典型亚热带季风常绿阔叶,常称季雨林。选择6个典型沟谷季雨林群落,开展群落生态学和生物地理学的研究,结果表明:(1)群落组成以典型的热带性科属为特征,如樟科Lauraceae、壳斗科Fagaceae、山茶科Theaceae、茜草科Rubiaceae、金缕梅科Hamamelidaceae等;种子植物属的地理成分以热带-亚热带成分占优势,占总属数的64.71%—77.94%,高于同纬度地区其他山体,接近甚至高于南亚热带季风常绿阔叶林中的热带性成分。(2)群落结构具有多优势种及明显的特征性标志种,与具单优势种或少数优势种的亚热带常绿阔叶林有明显差异。(3)Shannon-Wiener指数为4.44—5.46之间,物种多样性较丰富,表现出明显的南亚热带植被特征。(4)其它热带雨林性质的特征还包括:大型木质藤本,板根现象,绞杀现象,滴水叶尖,丰富的寄生、附生植物、兰科植物、树蕨等。整体上,井冈山地区亚热带沟谷季雨林群落具有热带雨林向亚热带常绿阔叶林过渡的明显特征,与南亚热带季雨林性质相似,在演替上常被称为侵入群落,或为历史时期长期演化形成的超地带性植物群落。     

大果马蹄荷(Exbucklandia tonkinensis)群落的纬度地带性

大果马蹄荷主产南亚热带至中亚热带南缘,南至海南岛,北至罗霄山脉中段的井冈山、桃源洞地区,是常绿阔叶林的特征种。以纬度地带性(海南霸王岭、广东黑石顶、广东南岭、江西金盆山、江西井冈山、湖南桃源洞)为依托,选定6个具代表性的大果马蹄荷群落开展群落生态学研究,结果表明:(1)各样地物种多样性较高,尤以金盆山蕨类植物9科10属11种、种子植物42科78属128种和桃源洞蕨类植物9科11属12种、种子植物41科79属134种最为丰富。群落组成的优势科主要为金缕梅科、壳斗科、樟科、山茶科、杜鹃花科、山矾科等。(2)从区系特征和环境梯度看,大果马蹄荷群落以南亚热带为分布中心,向南或向北其物种多样性Simpson指数、Shannon-Wiener指数及相应的均匀度指数均呈下降趋势,其中霸王岭、黑石顶、南岭、金盆山、井冈山、桃源洞的Shannon-Wiener指数分别为3.453、4.021、4.130、3.790、3.415、3.712。(3)群落相似性聚类分析显示群落随纬度和随海拔高度形成两个梯度系列,一是以黑石顶、金盆山、井冈山、桃源洞的纬度地带性为一支,相似性系数0.51;二是以南岭和霸王岭聚成海拔梯度较高的另一支,但其相似性系数0.50,为0.33—0.48。(4)大果马蹄荷群落种类组成在区系性质上很相似,具有明显的南亚热带特征;同时,受海拔、地形、气温、降雨条件等因素的影响,种子植物属的热带成分随纬度增加而呈波动性下降趋势。(5)大果马蹄荷种群在各群落中的重要值水平和径级结构表现出一致性,在纬度地带性差异上无明显的相关性。霸王岭大果马蹄荷的径级结构为增长型,但重要值排名为32,说明向南分布该种群优势度明显下降;在南岭、黑石顶、金盆山、桃源洞该种群优势度较大,且为稳定型种群;在井冈山该群落受到人为干忧,大果马蹄荷的重要值排名第1,但为衰退型种群。     

DNA variation at the rp49 gene region of Drosophila simulans: evolutionary inferences from an unusual haplotype structure.

An approximately 1.3-kb region including the rp49 gene plus its 5' and 3' flanking regions was sequenced in 24 lines of Drosophila simulans (10 from Spain and 14 from Mozambique). Fifty-four nucleotide and 8 length polymorphisms were detected. All nucleotide polymorphisms were silent: 52 in noncoding regions and 2 at synonymous sites in the coding region. Estimated silent nucleotide diversity was similar in both populations (pi = 0.016, for the total sample). Nucleotide variation revealed an unusual haplotype structure showing a subset of 11 sequences with a single polymorphism. This haplotype was present at intermediate frequencies in both the European and the African samples. The presence of such a major haplotype in a highly recombining region is incompatible with the neutral equilibrium model. This haplotype structure in both a derived and a putatively ancestral population can be most parsimoniously explained by positive selection. As the rate of recombination in the rp49 region is high, the target of selection should be close to or within the region studied.     

Evolution of the ovine MHC DQA region

Southern hybridisation was used to define an apparent gene duplication event at the ovine DQA2 locus. Approximately 500 sheep from five different breeds were genotyped at their DQA1 and DQA2 loci. A subset of these were selected for further characterisation. Southern hybridisation of TaqI digested DNA revealed no DQA1 region in some sheep. It was also noted in these DQA1 null animals the DQA2 specific probe hybridised to two bands. An EcoRV-RFLP designed to distinguish copy number confirmed this duplication of the DQA2 region. The results showed that the duplication was exclusively associated with the DQA1 null haplotype and occurred only in alleles DQA2-F, -G, -I and -J. Comparison with bovine MHC genes revealed that they also contained a DQA1 null haplotype and that this haplotype was associated with a putative DQA3 gene. The potential for an ovine DQA3 locus is discussed.     

Major-histocompatibility-complex DRB genes of a New-World monkey, the cottontop tamarin (Saguinus oedipus).

The DRB region of the human and great-ape major histocompatibility complex displays not only gene but also haplotype polymorphism. The number of genes in the human DRB region can vary from one to four, and even greater variability exists among the DRB haplotypes of chimpanzees, gorillas, and orangutans. Accumulating evidence indicates that, like gene polymorphism, part of the haplotype polymorphism predates speciation. In an effort to determine when the gene haplotype polymorphisms emerged in the primate lineage, we sequenced three cDNA clones of the New-World monkey, the cottontop tamarin (Saguinus oedipus). We could identify two DRB loci in this species, one (Saoe-DRB1) occupied by apparently functional alleles (*0101 and *0102) which differ by only two nucleotide substitutions and the other (Saoe-DRB2) occupied by an apparent pseudogene. The Saoe-DRB2 gene contains an extra sequence derived from the 3' portion of exon 2 and placed 5' to this exon. This sequence contains a stop codon which makes the translation of the bulk of the Saoe-DRB2 gene unlikely. Preliminary Southern blot hybridization analysis with probes derived from these two genes suggests that both the DRB gene polymorphism and the haplotype polymorphism in the cottontop tamarin may be low. In most individuals the DRB region of this species probably consists of three genes. Comparisons of the Saoe-DRB sequences with those of other primates suggest that probably all of the DRB genes found until now in the Catarrhini were derived from a common ancestor after the separation of the Catarrhini and Platyrrhini lineages. The extant DRB gene and haplotype polymorphism may therefore have been founded in the mid-Oligocene some 33 Mya.     

Genetic variation of mitochondrial DNA in Chinese populations of Pectinophora gossypiella (Lepidoptera: Gelechiidae)

The pink bollworm Pectinophora gossypiella is an invasive pest insect that has successfully established populations in many cotton growing regions around the world. In this study, the genetic diversity and population structure of Chinese populations of P. gossypiella were evaluated using mitochondrial DNA sequence data (COII and Nad4). For comparison, individuals of Pakistan and America were also sequenced at the same two mtDNA regions. Extremely low genetic variation was observed in the two mitochondrial regions among all populations examined. Most of the populations harbored only one to two haplotypes. Although the Nad4 region showed relatively high haplotype diversity and nucleotide variation, ranging from 0.363 to 0.591 and from 0.00078 to 0.00140, respectively, there were only three haplotypes observed in this region. COII and Nad4 haplotype networks shaved one or two common haplotype(s) forming the center of a star-shaped phylogeny. Pairwise tests showed that most of the populations were not significantly differentiated from each other. The Chinese populations were differentiated from the Pakistani and American populations in the Nad4 region. The low level of population genetic variation of P. gossypiella is attributed to invasion bottlenecks, which may have been subsequently strengthened by its nonmigratory biology and the mosaic pattern of agricultural activities.     

Discovery of a new HBB haplotype <Emphasis Type="Italic">w2</Emphasis> in a wild-derived house mouse, <Emphasis Type="Italic">Mus musculus</Emphasis>

Genetic characterization of a wild-derived house mouse, Mus musculus, originally collected near Lake Balkhash in the Republic of Kazakhstan, was performed by examining protein polymorphisms and nucleotide sequences for the hemoglobin beta chain (HBB) subunits. Protein electrophoresis, which was performed on a cellulose-acetate plate, showed an independent mobility pattern representing a new, previously undiscovered haplotype. Neighbor-joining analyses of the HBB adult genes, i.e., HBB-T1 and HBB-T2, and the intergenic spacer region showed that the Lake Balkhash mouse possessed genomic components that were mixed from different haplotypes. Compared to the previously determined HBB haplotypes, d, p, and w1, the HBB-T1 gene and ca. 11 kb of the spacer region were most similar to the w1 haplotype; however, the remainder of the spacer region and the HBB-T2 gene were most similar to the d haplotype but may represent a still uncharacterized and divergent haplotype. The recombination event is predicted to have occurred 2.5 kb upstream of the HBB-T2 gene and may have occurred through intersubspecific hybridization between mice of the musculus subspecies group (with the w1 haplotype) and the castaneus subspecies group (with the d-like haplotype). Alternatively, an unknown subspecies group that is equidistantly divergent from each of these subspecies groups may have been involved. Our findings suggest reticulate evolution among the subspecies groups during the evolution of M. musculus.     

Genetic variability in the complete mitochondrial control region of the Eurasian otter (Lutra lutra) in the Iberian Peninsula

Sequencing of the complete mitochondrial DNA control region from 31 samples of the Eurasian otter, Lutra lutra , enabled us to establish the length and structure of this fragment, as well as to describe, for the first time, the RS3 repetitive region located at the 3' end. In addition, genetic variability of the 5' end was examined in 63 individuals, 57 of which were wild otters from the Iberian Peninsula and six captive reared otters. This analysis resulted in extremely low variability. All the samples from the Iberian Peninsula share a single haplotype, Lut 1, the most common haplotype in Europe. Captive otters showed two haplotypes: Lut 3, which has been described in wild otters from eastern Germany, and Lut 6, an haplotype not described to date. Higher variability was observed in the repetitive RS3 region. The tandem repeat was composed of an array of ten repeat units of 22 bp with differences in the repetitive motifs that differed in the arrays of different specimens. In total, 20 different haplotypes from 31 individuals were found. However, the geographical distribution of these haplotypes did not generate a phylogeographical signal. © 2005 The Linnean Society of London, Biological Journal of the Linnean Society , 2005, 86 , 397–403.