Mitochondrial DNA variation in cattle of South China: origin and introgression

Ten restriction endonucleases were used to investigate the mitochondrial DNA restriction fragment length polymorphism (mtDNA RFLP) of 11 native cattle breeds and one cultivated cattle breed in South China. Twenty-three restriction morphs were detected, which can be sorted into five haplotypes. A phylogenetic tree of the haplotypes was constructed by using the 'upgMa' method. Our study showed that haplotype I and II are identical to the zebu (Bos indicus) and taurine (Bos taurus) haplotypes, respectively. Zebu and taurine were the two major origins of cattle populations in South China, and the zebu probably had more influence on the native cattle population than taurine did. Haplotype III is identical to haplotype I of yak (Bos grunniens), which was only detected in the Diqing cattle breed. Haplotype IV was detected for the first time. This haplotype, found only in Dehong cattle, might be from an independent domestication event, probably from another Bos indicus population. Divergence of haplotypes I and IV occurred about 268,000-535,000 years ago, much earlier than the 10,000-year history of cattle husbandry. Our results also suggest a secondary introgession of mtDNA from yak to Diqing cattle.     

基于线粒体COI基因序列的大豆食心虫中国东北地理种群遗传多样性分析

【目的】大豆食心虫Leguminivora glycinivorella (Matsumura)是一种危害大豆的主要害虫,在中国北方地区危害较重。本研究旨在探讨大豆食心虫在中国东北不同地理种群间的遗传变异。【方法】测定了10个不同地理种群153个个体的线粒体细胞色素氧化酶亚基Ⅰ (mtCOI)基因的657 bp序列,利用DnaSP 5. 0和Arlequin 3. 5. 1. 2等软件对大豆食心虫种群间的遗传多样性、基因流水平和分子变异进行分析。【结果】结果表明：10个地理种群间的COI基因共有36个变异位点和17个单倍型,其中1个单倍型为10个种群所共享。总种群的单倍型多样性指数Hd为0.456,各地理种群单倍型多样度范围在0~0.634之间。总群体的固定系数Fst为0.12545,遗传分化系数Gst为0.06326,总基因流Nm为3.49,且各种群间的基因流均大于1,种群间基因交流的水平较高。【结论】大豆食心虫种群内遗传多样性水平处于中低等水平。总群体和各种群的Tajima’s D检验结果皆不显著,说明中国东北地区大豆食心虫在较近的历史时期内没有出现种群扩张现象。AMOVA分子变异分析结果表明,大豆食心虫的遗传分化主要来自种群内部,而种群间未发生明显的遗传分化。各地理种群的单倍型在系统发育树上和中介网络图上散布在不同的分布群中,缺乏明显的地理分布格局。各种群的遗传距离与地理距离之间没有显著线性相关性,种群间的基因交流并未受到地理距离的影响。     

贵州从江侗族Y-DNA及线粒体DNA 序列多态性分析

为分析贵州从江侗族父系及母系遗传结构,探讨其起源及迁徒, 通过聚合酶链式反应-限制性片段长度多态性(PCR-RFLP), 研究贵州从江侗族无亲缘关系个体由10个单核苷酸位点(SNPs)组成的Y染色体单倍型及11个单核苷酸位点组成的线粒体DNA单倍群频率。结果显示, 从40份男性样本的Y-SNP基因分型中,得到H6 、H11、H14 共3种单倍型;H11的频率为92.5%;通过对线粒体DNA基因分型,得到6种单倍群,有75%的个体能明确分类其所携带的单倍群特征,说明贵州从江侗族父系遗传构成相对简单。通过主成分分析,证明贵州从江侗族与其他的壮侗语族人群相聚,母系遗传结构复杂,无C单倍群分布可能为该民族特征之一。Abstract: To study the patrilineal and matrilineal genetic structure and the origin of Dong Ethnic of Congjiang Guizhou. Study the distribution of Y-chromosome haplotypes which consisted of 10 SNPs of Y-DNA and mtDNA haplogroups consisted of 11 SNPs by using PCR-RFLP method. The result is three haplotypes H6,H11,H14 were detected, the frequency of H11 is 92.5%. Six haplogroups were identified by mtDNA analysis, 75% of the people can be identified. The patrilineal genetic structure of Dong of Guizhou is simple, Principle component indicated that the structure is closer to Zhuang-Dong branch of Sino-Tibetan language family. The matrilineal genetic structure of Dong of Guizhou is complicated.     

我国根瘤蚜mtDNA COⅠ遗传多样性与系统发育

通过线粒体DNA COⅠ多态性研究了我国根瘤蚜Daktulosphaira vitifoliae Fitch的遗传分化与系统发育,并将我国根瘤蚜单倍型与GenBank中已发表的85个单倍型进行了聚类分析。结果表明：序列中A,C,T,G 4种核苷酸的比例分别为34.8%,15.8%,39.2%和10.2%, 29 个变异位点中单一多态位点 12 个,简约信息位点17 个。确定了 13 种单倍型,检测5种单倍型,其中上海群体单倍型相对丰富,且上海葡萄根瘤蚜群体与其他3个群体之间没有共享单倍型。同时上海群体与其他3个群体的遗传距离最大（0.039~0.040）,Nm最小（0.02）,在分子系统发育树和单倍型网络图上为独立分支,说明我国根瘤蚜至少有两个独立的起源。     

Phylogeny of the green lacewing Chrysoperla nipponensis species‐complex (Neuroptera: Chrysopidae) in China,based on mitochondrial sequences and AFLP data

Abstract Several studies have indicated that the green lacewing, Chrysoperla nipponensis (Neuroptera: Chrysopidae) may include more than one valid species. We investigated the phylogenetic status of Chrysoperla nipponensis s.l. in China and Japan using mitochondrial sequences and AFLP data. The molecular phylogenetic analyses based on mitochondrial genes showed that the C. nipponensis species‐complex comprises four clades, each having high support values. In addition, the phylogenetic tree based on AFLP data indicates that the species‐complex comprises three groups. These results confirm that C. nipponensis s.l. comprises at least three genetically distinct clades and suggests that two of these clades may be closely related to populations of C. nipponensis in Japan. However, these clades cannot be recognized as species until analysis of their courtship songs has been completed.     

Ancient human mtDNA genotypes from England reveal lost variation over the last millennium

We analysed the historical genetic diversity of human populations in Europe at the mtDNA control region for 48 ancient Britons who lived between ca AD 300 and 1000, and compared these with 6320 modern mtDNA genotypes from England and across Europe and the Middle East. We found that the historical sample shows greater genetic diversity than for modern England and other modern populations, indicating the loss of diversity over the last millennium. The pattern of haplotypic diversity was clearly European in the ancient sample, representing each of the modern haplogroups. There was also increased representation of one of the ancient haplotypes in modern populations. We consider these results in the context of possible selection or stochastic processes.     

基于线粒体COⅠ基因序列的中国二点委夜蛾遗传多态性分析

二点委夜蛾Athetis lepigone是2005年首次在河北省发现危害夏玉米苗的新害虫, 2011年7月在河北、 河南、 山东、 山西、 安徽和江苏6省47市夏玉米苗期大面积暴发成灾, 严重威胁玉米生产。为了从种群水平探讨该虫暴发成灾的机制, 我们通过分析线粒体细胞色素氧化酶亚基Ⅰ(mtCOⅠ）基因序列来研究不同地区二点委夜蛾种群的进化关系。本研究采集了河北、 河南、 山东和山西等地的19个不同地理种群样本, 用同源序列比对的方法分析样本mtCOⅠ基因片段, 利用DnaSP 5.0软件和Arlequin 3.5软件对不同地理种群间的mtCOⅠ单倍型多样性分析和Tajima’s D中性检测, 建立了单倍型邻接（N-J）系统发育进化树和单倍型网络图。结果表明, 在203头个体的658 bp mtCOⅠ基因片段中, 得到17种单倍型和18个变异位点, 河北省的二点委夜蛾的单倍型多态性最丰富, 而河南、 山东和山西3省采集的二点委夜蛾样品其单倍型均有与河北种群单倍型一致的类型。二点委夜蛾不同地理种群间基因流水平较高, 种群间没有明显的遗传分化, 并且在较近的历史时期未经历明显的种群扩张。     

The role of waterholes as 'refugia' in sustaining genetic diversity and variation of two freshwater species in dryland river systems (Western Queensland, Australia)

1. Episodic floods and extended low or no flow periods characterise dryland river systems in Western Queensland, Australia. During protracted intervals between floods, rivers consist of a series of isolated waterholes, which serve as ‘refugia’ for aquatic species and much of the channel is dry. We categorised these waterholes into ‘main waterholes’, which are located in the main part of the river channel and ‘satellite waterholes’, which are located in distributary river channels. 2. We used mitochondrial sequences and allozymes to investigate levels of genetic diversity and patterns of connectivity among waterholes for two obligate freshwater species: Macrobrachium australiense (Decapoda: Palaemonidae) and Notopala sublineata (Gastropoda: Viviparidae). 3. We sampled 31 waterholes for M. australiense and 12 for N. sublineata. Based on a 505‐bp fragment of cytochrome oxidase subunit I, we identified 54 haplotypes in a sample of 232 individuals for M. australiense and based on a 457‐bp fragment of the same gene, 36 haplotypes in a sample of 145 individuals for N. sublineata. 4. Both nuclear and mitochondrial genetic data sets indicated that estimates of genetic diversity were not different in populations inhabiting main and satellite waterholes for either species. Also, there was generally very limited genetic differentiation among populations at any site. 5. We suggest that levels of connectivity among populations inhabiting waterholes at most sites are higher than expected. High levels of connectivity may help to maintain overall high levels of genetic diversity as well as low levels of genetic differentiation among waterholes within sites.     

多浪羊mtDNA D-loop区遗传多样性及系统发育分析

以多浪羊为研究对象,分析绵羊线粒体D-loop区的遗传多样性,为研究多浪羊的起源和进化历史奠定基础。结果显示,多浪羊线粒体DNA D-loop序列长度为945~1 039 bp,A、T、G和C含量分别为29.4%、27.7%、17.7%和25.1%,其中A+T为57.1%,G+C为42.8%。研究获得了26种单倍型,56个多态位点,其中单一多态位点42个,简约信息位点14个。平均核苷酸差异数k为5.289,核苷酸多样度Pi为0.02 415,核苷酸多样度较低,说明多浪羊的遗传多样性贫乏,应采取重点措施予以保护。另外研究发现多浪羊经历过群体扩张,其母系起源除A、B和C世系外,可能存在D或E世系。