Qaidam cattle are a typical Chinese native breed inhabiting northwest China. They bear the characteristics of high cold and roughage tolerance, low-oxygen adaptability and good meat quality. To analyze the genetic diversity of Qaidam cattle, 60 samples were sequenced using whole-genome resequencing technology, along with 192 published sets of whole-genome sequencing data of Indian indicine cattle, Chinese indicine cattle, North Chinese cattle breeds, East Asian taurine cattle, Eurasian taurine cattle and European taurine cattle as controls. It was found that Qaidam cattle have rich genetic diversity in Bos taurus, but the degree of inbreeding is also high, which needs further protection. The phylogenetic analysis, principal component analysis and ancestral component analysis showed that Qaidam cattle mainly originated from East Asian taurine cattle. Qaidam cattle had a closer genetic relationship with the North Chinese cattle breeds and the least differentiation from Mongolian cattle. Annotating the selection signals obtained by composite likelihood ratio, nucleotide diversity analysis, integrated haplotype score, genetic differentiation index, genetic diversity ratio and cross-population extended haplotype homozygosity methods, several genes associated with immunity, reproduction, meat, milk, growth and adaptation showed strong selection signals. In general, this study provides genetic evidence for understanding the germplasm characteristics of Qaidam cattle. At the same time, it lays a foundation for the scientific and reasonable protection and utilization of genetic resources of Chinese local cattle breeds, which has great theoretical and practical significance.

Yak (Bos grunniens) is a unique livestock animal originating from the Qinghai-Tibet Plateau in China. In the current study, we investigated the maternal genetic diversity, differentiation and phylogeny of wild yak population and four domestic yak breeds (Qinghai-Gaoyuan, Huanhu, Xueduo, and Yushu) in Qinghai, China by analyzing 166 mitochondrial cytochrome b (Cytb) gene sequence variations. Our results indicated that the haplotype and nucleotide diversities of wild yak were 0.883±0.044 and 0.004±0.002, while the total haplotype and nucleotide diversities of four Qinghai domestic yak breeds were 0.646±0.040 and 0.003±0.001, respectively. Among the four Qinghai domestic yak breeds, the haplotype diversity was found to be highest in Yushu yak breed (Hd = 0.770±0.053), while the lowest was recorded in Huanhu yak breed (Hd = 0.501±0.088). Estimates of FST values showed a moderate genetic differentiation between wild yak and Huanhu yak (FST = 0.058) as well as that between Huanhu yak and Yushu yak breeds (FST = 0.052), but a weak genetic differentiation was observed between the other yak breeds/populations (-0.021＜FST＜0.037). Additionally, the clustering analysis based on RST values showed that Xueduo yak and Huanhu yak were clustered into one group, and each of the other three yak breeds/populations was separated into one group, respectively. Overall, the clustering relationship between wild yak and Yushu yak was closer. Maternal phylogenetic analysis showed that wild yak and four local yak breeds/populations in Qinghai represented in three maternal lineages (Mt-Ⅰ, Mt-Ⅱ, and Mt-Ⅲ), indicating three maternal origins in yak. Our study would provide valuable information for the conservation and utilization of wild yak and Qinghai domestic yak breeds.

The Qinghai Province of China is located in the northeast region of the Qinghai-Tibetan Plateau (QTP) and carries abundant yak genetic resources. Previous investigations of archaeological records, mitochondrial DNA, and Y chromosomal markers have suggested that Qinghai was the major center of yak domestication. In the present study, we examined the genomic diversity, differentiation, and selection signatures of 113 Qinghai yak, including 42 newly sequenced Qinghai yak and 71 publicly available individuals, from nine yak breeds/populations (wild, Datong, Huanhu, Xueduo, Yushu, Qilian, Geermu, Tongde, and Huzhu white) using high-depth whole-genome resequencing data. We observed that most of Qinghai yak breeds/populations have abundant genomic diversity based on four genomic parameters (nucleotide diversity, inbreeding coefficients, linkage disequilibrium decay, and runs of homozygosity). Population genetic structure analysis showed that Qinghai yak have two lineages with two ancestral origins and that nine yak breeds/populations are clustered into three distinct groups of wild yak, Geermu yak, and seven other domestic yak breeds/populations. F (ST) values showed moderate genetic differentiation between wild yak, Geermu yak, and the other Qinghai yak breeds/populations. Positive selection signals were detected in candidate genes associated with disease resistance (CDK2AP2, PLEC, and CYB5B), heat stress (NFAT5, HSF1, and SLC25A48), pigmentation (MCAM, RNF26, and BOP1), vision (C1QTNF5, MFRP, and TAX1BP3), milk quality (OPLAH and GRINA), neurodevelopment (SUSD4, INSYN1, and PPP1CA), and meat quality (ZRANB1), using the integrated PI, composite likelihood ratio (CLR), and F (ST) methods. These findings offer new insights into the genetic mechanisms underlying target traits in yak and provide important information for understanding the genomic characteristics of yak breeds/populations in Qinghai.

Nangqian grey yak (Bos grunniens) is a unique yak population in Qinghai Province, China. In this study, the whole mitogenome sequences of 18 Nangqian grey yaks were sequenced based on the next-generation sequencing (NGS) technology and annotated. The total length of whole mitogenome sequence is between 16.323 bp and 16.325 bp, including a non-coding control region (D-loop region), 22 tRNA genes, 13 protein-coding genes and two rRNA genes (12S rRNA and 16S rRNA). Maternal genetic diversity based on the mitogenome variations was analyzed. A total of 12 haplotypes were identified among 18 complete mitogenome sequences, the haplotype diversity and nucleotide diversity of Nangqian grey yak were 0.948±0.033 and 0.001±0.001, respectively. Compared with the wild yak population and six other domestic yak breeds/populations in China, the haplotype diversity of Nangqian grey yak population was higher, indicating abundant maternal genetic diversity in Nangqian grey yak. The phylogenetic tree showed that Nangqian grey yak was most closely related to Tibet alpine, Xueduo, Changtai, Sibu, Zhongdian, Tianzhu white, Ashdan, Jinchuan, Jiulong, Pamir, Pali, Qinghai plateau, Huanhu, Datong, Bazhou and wild yak breeds/populations, closer to Chawula, Muli, Gannan, Niangya and Yushu yak breeds, but far away from other yak breeds (i.e. Leiwuqi and Maiwa yak).

为探究柴达木黄牛的母系遗传多样性及遗传背景,本研究随机选取柴达木黄牛5个主产区268个个体,通过PCR方法和直接测序技术得到其mtDNA Cyt b基因全序列,使用生物信息学软件分析其遗传多样性、分化及母系起源,进而在分子水平上揭示其母系遗传多样性水平、分化程度及母系遗传背景.结果表明:柴达木黄牛Cyt b基因核苷酸序列长度为1140 bp,比对分析共检测到29个核苷酸多态位点,其中单一多态位点4个,简约信息位点25个;依据序列间核苷酸变异共确定了12种单倍型,其中优势单倍型为H2,品种单倍型多样度为0.5882±0.0300,核苷酸多样度为0.0040±0.0022,表明柴达木黄牛具有较丰富的母系遗传多样性.柴达木黄牛品种内5个群体间分化指数Fst值在-0.0104～0.1618,提示品种内群体间分化程度存在差异,其中格尔木群体与乌兰群体间分化程度最大(Fst=0.1618),大柴旦群体和茫崖群体间的分化程度最小(Fst=-0.0104).基于UPGMA法的品种内群体间聚类关系表明,柴达木黄牛品种内5个群体可聚为2类,其中格尔木群体与都兰群体最先聚在一起,大柴旦群体与茫崖群体也最先聚为一起,随后它们再聚为1类,而乌兰群体单独为另一类,2类最后聚为一大类.系统发育分析表明,柴达木黄牛由普通牛和瘤牛2个母系遗传支系组成,表明柴达木黄牛有普通牛和瘤牛2个母系起源且以普通牛起源为主.此外,研究发现,茫崖、乌兰、都兰各群体均有1个个体为牦牛mtDNA Cyt b单倍型序列类型,占总头数的1.12％,提示柴达木黄牛品种中存在一定程度的牦牛基因渗入.

抗缪勒管激素(AMH)是一种主要由睾丸支持细胞和卵巢颗粒细胞分泌的生殖激素,在胎儿生殖器官发育、精子生成、卵泡发生等生物学过程中起着重要作用.本文从牛AMH的结构与生理功能、母牛血液AMH浓度的影响因素以及AMH在母牛繁殖中的应用等方面进行了综述.

旨在从分子水平上探究野牦牛及青海地方牦牛品种的母系遗传多样性、群体遗传结构、亲缘关系和遗传背景.本研究在测定青海省4个地方牦牛品种(即青海高原、环湖、雪多和玉树牦牛)22条全线粒体基因组(Mitoge-nome)序列的基础上,从GenBank下载了已公布的野牦牛及上述4个地方牦牛品种的142条相应序列,使用BioEdit 7.2.5、Arlequin 3.11和Network 10.1等软件对共计164条线粒体基因组序列进行综合分析.结果显示:1)根据序列间核苷酸变异共确定了 115种单倍型,其中野牦牛和青海地方牦牛品种分别拥有22种和93种单倍型;在野牦牛和青海高原、环湖、雪多、玉树牦牛中分别检测到22、26、18、23、19种特有的单倍型.遗传多样性分析显示,野牦牛单倍型多样度最高(0.992 8±0.014 4),且高于4个青海地方牦牛品种的单倍型多样度(0.973 1±0.007 7);4个青海地方牦牛品种单倍型多样度大小依次为:雪多牦牛(0.988 5士0.012 6)、玉树牦牛(0.975 8士0.018 7)、青海高原牦牛(0.973 0±0.016 6)和环湖牦牛(0.939 3±0.027 8).2)野牦牛与环湖牦牛之间的固定分化指数值(FsT值)最大(0.041 2),分化程度最高,而与玉树牦牛间的FST值最小(-0.008 8),分化程度最低.青海4个地方牦牛品种中,雪多牦牛与青海高原牦牛之间F ST值最大(0.035 8),分化程度最高,而雪多牦牛与环湖牦牛间FST值最小(0.011 2),分化程度最低.3)聚类分析显示,4个青海地方牦牛品种各自为1类,存在明显的母系遗传差异.相比而言,环湖牦牛和雪多牦牛聚类较近,青海高原牦牛和玉树牦牛聚类较近,而野牦牛与玉树牦牛聚类关系更近,各品种(群体)间的聚类结果与其分化程度、地理分布一致.4)系统发育分析表明,115种单倍型分布在3个大的母系遗传分支(即Mt-Ⅰ、Mt-Ⅱ和Mt-Ⅲ),其中Mt-Ⅰ支系所占比例为72.17％,由A、B、E和F 4种单倍型组构成;Mt-Ⅱ支系包括C、D和H 3种单倍型组,占26.09％;而Mt-Ⅲ支系只包含G单倍型组,由雪多牦牛和野牦牛所拥有,所占比例为1.74％,提示牦牛有3个母系起源.综上所述,野牦牛和青海4个地方牦牛品种均具有丰富的母系遗传多样性,其多样性水平由高到低依次为野牦牛、雪多牦牛、玉树牦牛、青海高原牦牛和环湖牦牛.青海4个地方牦牛品种间及与野牦牛间的遗传分化程度均较弱,但各自拥有特有的母系遗传信息,存在明显的母系遗传差异.野牦牛和青海家牦牛品种由3个母系支系组成,推测牦牛有3个母系起源.

为从分子水平上揭示青海省囊谦青牦牛的母系遗传多样性、群体结构及遗传背景,对31头囊谦青牦牛mtDNA D-loop区序列进行PCR扩增、测序和序列比对分析,确定序列变异位点和单倍型数目,计算单倍型多样度和核苷酸多样度大小,并进行系统发育分析.结果表明,在囊谦青牦牛618 bp D-loop区序列分析中,共检测到34个多态位点,包括8个单一多态位点和26个简约信息位点.根据序列间核苷酸变异共确定了12种单倍型,单倍型多样度和核苷酸多样度分别为0.846±0.055和0.011±0.005.与野牦牛及我国其他18个家牦牛品种相比,囊谦青牦牛群体核苷酸多样度和单倍型多样度值均较低,表明囊谦青牦牛母系遗传多样性水平较低.以美洲野牛为外群构建的系统发育树结果显示,囊谦青牦牛群体的12种单倍型分布在3种单倍型组A、C、D中,且聚为2个大的分支,提示囊谦青牦牛由2个母系支系组成,拥有2个母系起源.综上,囊谦青牦牛群体母系遗传多样性较低,由2个母系支系组成,推测其有2个母系起源.

The white yak, a type of unique and valuable farm animals on the Qinghai-Tibet Plateau, are mainly distributed in Tianzhu (County of Gansu Province), Menyuan, Huzhu and Ledu (three Counties of Qinghai Province) in China. In the present study, the Y-chromosomal genetic diversity, differentiation and phylogeny of three Chinese white yak breeds/populations (Tianzhu, Huzhu and Menyuan) were comprehensively explored using five Y-SNPs ( SRY4 , USP9Y , UTY19 , AMELY3 and OFD1Y10 ) and one Y-STR ( INRA189 ) markers. The results showed that six Y-haplotypes (H1Y1, H9Y1, H10Y1, H11Y2, H12Y2 and H13Y2) were identified in 97 male yak from three white yak breeds/populations. Among these haplotypes, H1Y1, H10Y1 and H11Y2 were shared by all of breeds/populations and H12Y2 was shared by Tianzhu and Huzhu populations. However, H9Y1 and H13Y2 haplotypes were only detected in Menyuan and Tianzhu white yak populations, respectively. The Y-haplotype diversity was maximum in Huzhu white yak (0.7500 ± 0.0349), the medium in Tianzhu white yak (0.6881 ± 0.0614) and the lowest in Menyuan white yak (0.5720 ± 0.0657). The total Y-haplotype diversity of three white yak breeds/populations was 0.7567 ± 0.0233, indicating rich paternal genetic diversity in white yak. The F ST values showed a moderate differentiation between Tianzhu and Menyuan ( F ST = 0.0763, P < 0.05) populations, but a weak differentiation between Huzhu and Tianzhu white yak breeds/populations ( F ST = 0.0186, P > 0.05) and Huzhu and Menyuan ( F ST = − 0.005, P > 0.05) populations. The clustering analysis revealed a close genetic relationship between Huzhu and Menyuan white yak, both were far from Tianzhu white yak breed. The phylogenetic analyses showed that white yak had two Y-haplogroups/lineages (Y1 and Y2) with two potential paternal origins. The findings of present study provide new insight into the basic information for the formulation of molecular breeding programs of white yak. Moreover, it also contributes to the conservation and utilization of this special animal genetic resource.

[目的]从分子水平上探究青海省果洛藏族自治州3个牦牛群体(即达日、玛沁和岗龙群体)的母系遗传多样性水平、分化状况、聚类关系及其遗传背景.[方法]对33头岗龙牦牛线粒体DNA(mtDNA)D-loop区序列进行了测定,后从GenBank中下载了已报道的37条达日牦牛和32条玛沁牦牛的相应序列,对共计102条mtDNA D-loop序列进行综合分析.[结果]根据638 bp D-loop区分析序列间核苷酸变异共确定了32种单倍型,其中达日、玛沁和岗龙牦牛群体分别拥有特有单倍型8、6和8种.3个牦牛群体总的单倍型多样度和核苷酸多样度为0.921±0.014和0.020±0.010,其中岗龙牦牛的单倍型多样度最高(0.951±0.019),达日牦牛的单倍型多样度居中(0.901±0.034),而玛沁牦牛的单倍型多样度最低(0.887±0.033).岗龙牦牛与达日牦牛(Fst=0.118;Nm=1.869)、玛沁牦牛(Fst=0.129;Nm=1.688)群体间均呈中等遗传分化水平,基因交流贫乏,而达日牦牛和玛沁牦牛间(Fst=0.021;Nm=11.655)分化程度很弱,基因交流相对频繁.达日牦牛与玛沁牦牛最先聚为一类,后与岗龙牦牛再聚为一类.3个牦牛群体均由2个母系遗传分支组成,推测各群体均有2个母系起源.[结论]青海省果洛藏族自治州3个牦牛群体均拥有特有的母系遗传信息,岗龙、达日牦牛群体相比玛沁牦牛具有更丰富的母系遗传多样性;岗龙牦牛与达日、玛沁牦牛群体间遗传分化程度较高,而达日牦牛和玛沁牦牛间分化水平较低;各群体均由2个母系遗传分支组成,推测其均有2个母系起源.

[目的]从分子水平上探究青海省格尔木牦牛的母系遗传多样性、群体遗传结构及其遗传背景.[方法]对49头格尔木牦牛mtDNA D-loop区部分序列进行了测定,后使用DnaSP 5.10.01、Arlequin 3.11和MEGA 5.05等生物信息学软件确定其多态位点和单倍型数目,计算核苷酸多样度和单倍型多样度大小,并进行系统发育分析.[结果]在截取的618 bp格尔木牦牛D-loop区分析序列中,排除1处插入(缺失)后共检测到45处多态位点,包括10处单一多态位点和35处简约信息位点;根据序列间核苷酸变异共确定了18种单倍型,其中单倍型H4为优势单倍型,核苷酸多样度为0.015±0.008,单倍型多样度为0.911±0.022.与野牦牛及大通、天祝、金川等其他家牦牛品种相比,格尔木牦牛群体单倍型多样度和核苷酸多样度值均较高,表明该群体具有丰富的母系遗传多样性.以美洲野牛为外群,邻接法(即NJ法)构建的系统发育树结果显示:格尔木牦牛群体18种单倍型分布在A、B、C、D和G5种单倍型组中,且聚为3个大的分支,提示格尔木牦牛由3个母系支系组成,拥有3个母系起源.[结论]格尔木牦牛群体具有丰富的母系遗传多样性,由3个母系支系组成,推测其有3个母系起源.

Wild yak (Bos mutus) is a vulnerable bovine species on the Qinghai–Tibetan Plateau (QTP). So far, most studies on molecular genetic diversity of wild yak have focused on autosomal and mtDNA variations based on small number of samples. In this study, we analyzed 84 D-loop and 24 whole mitogenome sequences of wild yak to further comprehensively explore its maternal genetic diversity and lineage composition. Meanwhile, using six yak Y-specific polymorphic markers (i.e., SRY4, USP9Y, UTY19, AMELY3, OFD1Y10 and INRA189), we assessed the paternal genetic diversity and lineage composition based on eight wild yak. Our results showed that wild yak exhibited abundant maternal genetic diversity with haplotype diversities of 0.9621 ± 0.0078 and 0.9928 ± 0.0144 in the D-loop and whole mitogenome sequences, respectively. Maternal phylogenetic analysis of wild yak uncovered three defined lineages (mt-I, mt-II and mt-III). Similarly, profuse paternal genetic diversity was observed in wild yak with Y-haplotype diversity (Hd) at 0.8214 ± 0.1007. Two Y-haplogroups (Y1 and Y2) with four Y-haplotypes (yH1-yH4) were identified in paternal phylogenetic analysis, indicating wild yak to be of two paternal lineages. This study of genetic diversity and lineage composition of wild yak would provide useful information for the genetic resource conservation and utilization of this vulnerable wild species.

Golmud yak (Bos grunniens) is mainly lived in the southern Qaidam Basin in Qinghai Province, China. Here, the complete mitogenome of the Golmud yak was firstly sequenced using Illumina high-throughput sequencing technique and the corresponding sequence characterization also has been identified. The mitogenome of Golmud yak was 16,324 bp length with an A + T-biased nucleotide composition (60.97%). It includes 22 tRNA genes, 13 protein-coding genes, 2 rRNA genes and a control region (D-loop region), which is consistent with that of other bovine species. The phylogenetic tree showed that Golmud yak was most closely related to Sibu, Huanhu, Zhongdian, Ashdan, Jiulong, Pali, Datong and Bazhou yak breeds, closer to Yushu, Niangya, Qinghai-Gaoyuan, Xueduo, Maiwa and wild yak, but far away from other yak breeds (i.e. Jinchuan, Gannan and Tianzhu white yak). The complete mitogenome sequence reported here would provide valuable information for breeding and improvement of Golmud yak.

Golmud yak (Bos grunniens) is mainly lived in the southern Qaidam Basin in Qinghai Province, China.Here, the complete mitogenome of the Golmud yak was fi rstly sequenced using Illumina high-throughput sequencing technique and the corresponding sequence characterization also has been identified.Th e mitogenome of Golmud yak was 16,324 bp length with an A + T-biased nucleotide composition (60.97%).It includes 22 tRNA genes, 13 protein-coding genes, 2 rRNA genes and a control region (D-loop region), which is consistent with that of other bovine species.Th e phylogenetic tree showed that Golmud yak was most closely related to Sibu, Huanhu, Zhongdian, Ashdan, Jiulong, Pali, Datong and Bazhou yak breeds, closer to Yushu, Niangya, Qinghai-Gaoyuan, Xueduo, Maiwa and wild yak, but far away from other yak breeds (i.e.Jinchuan, Gannan and Tianzhu white yak).Th e complete mitogenome sequence reported here would provide valuable information for breeding and improvement of Golmud yak.

为明确青海省祁连牦牛的母系遗传多样性水平、群体遗传结构组成及母系遗传背景,本研究对33头祁连牦牛的线粒体DNA(mtDNA)D-loop区序列进行测定,结合Genbank中已报道的22条祁连牦牛D-loop区序列,用BioEdit7.2.5、Arlequin3.11和Mega5等生物信息学软件对共计55条序列进行综合分析,探究其母系遗传多样性、群体遗传结构及系统发育关系.结果表明:在祁连牦牛mtDNA D-loop区692bp序列比对分析中,排除2处插入/缺失后共发现33处多态位点,其中单一多态位点3处、简约信息位点30处;共确定了17种单倍型,其中单倍型H2由19个个体共享,为优势单倍型;计算得到祁连牦牛群体的单倍型多样度为0.850±0.037,核苷酸多样度为0.016±0.008.与野牦牛及大通、青海高原、天祝等其他家牦牛品种相比,祁连牦牛群体单倍型多样度和核苷酸多样度值均较低,表明该群体的母系遗传变异较低,具有较低的母系遗传多样性.系统发育分析表明祁连牦牛的17种单倍型分属于5种单倍型组(即A、B、C、D和E),可分为2个大的母系支系(即支系Ⅰ和支系Ⅱ),推测其有2个母系起源.

[Objective] To reveal the maternal genetic diversity, population structure and genetic background of the Tanggulashan yak population in Qinghai Province, China at the molecular level. [Method] The mtDNA D-loop sequences of 52 Tanggulashan yaks PCR amplification, sequencing and were determined and analyzed by multiple sequence alignment to determine the sequence variation sites and the number of haplotypes and the corresponding indexes of haplotype diversity and nucleotide diversity were also calculated and phylogenetic analysis. [Result] In the 619 bp D-loop region, 31 polymorphic sites were detected after excluding 2 insertions（deletions）, including 5 single polymorphic sites and 26 parsimony information sites. A total of 13 haplotypes were identified based on nucleotide sequence variations with nucleotide diversity of 0.007±0.004 and haplotype diversity of 0.821 ± 0.043. Compared with wild yak and other 18 domestic yak breeds/populations in China, the values of haplotype diversity and nucleotide diversity of Tanggulashan yak population were relatively lower, indicating poor genetic variation and lower level of maternal genetic diversity. The phylogenetic tree constructed by NJ method showed that 13 haplotypes belonging to A, B, C, D, and E were clustered into two large maternal lineages（I and II） with lineage I accounting for 77%, indicating that Tanggulashan yak population is composed of two maternal lineages and has two maternal origins. [Conclusion] The Tanggulashan yak population had relatively lower maternal genetic diversity, consisting of two maternal lineages dominated by lineage I, which is speculated to have two maternal origins.

卵丘细胞是卵母细胞的重要支持细胞,卵丘细胞的质量影响卵母细胞的体外成熟和发育能力.低氧分压有利于牦牛(Bos grunniens)卵母细胞的体外成熟和发育能力,但是卵丘细胞是否参与该作用尚未见报道.为明确低氧分压对牦牛卵丘细胞转录组的影响,本研究在5％和20％O2的条件下进行牦牛卵丘细胞-卵母细胞复合体(cumulus-oocyte complex,COC)成熟培养,然后收集卵丘细胞进行转录组测序、差异表达基因筛选和qRT-PCR验证.本研究共获得8个转录组文库,总数据量56.17 Gb;基因表达分析表明,两组样品中共有13584个基因得到表达,筛选获得270个差异表达基因,其中229个差异基因在5％O2处理组高表达,41个差异基因在20％O2处理组高表达;基因本体论(Gene Ontology,GO)和KEGG通路富集分析表明,差异表达基因主要富集于糖酵解、卵丘细胞扩散和卵丘细胞-卵母细胞信号传导等生物学过程;在基因组未被注释的区域寻找新基因和新转录本,发现6711个新基因,7209个新转录本,其中829个新转录本具有蛋白编码能力.qRT-PCR结果验证了转录组测序结果准确.上述研究结果提示,低氧分压可能促使牦牛卵丘细胞的转录模式趋同于体内成熟环境,进而促进牦牛卵母细胞的成熟并提高其发育能力.本研究结果为深入研究氧分压对牦牛卵母细胞体外成熟中卵丘细胞-卵母细胞互作机理的影响提供了参考依据.

Tongde County is located in the southeast of Qinghai Province, China, harboring rich yak genetic resources. In the present study, the complete mitochondrial genome (mitogenome) of the Tongde yak (Bos grunniens) was firstly sequenced using Illumina sequencing technique and the corresponding sequence characterization was identified. Our results showed that the mitogenome of Tongde yak is a circular molecule with 16,323 bp length consisting of 37 genes (13 protein-coding genes, 2 rRNA genes, 22 tRNA genes) and a non-coding control region (D-loop), which is consistent with most bovine species. The overall nucleotide composition was found as: A (33.72%), T (27.27%), C (25.80%), and G (13.21%), respectively, yielding a higher AT content (60.99%). The complete mitogenome sequence of Tongde yak would provide useful information for further studies on its genetic resource conservation and molecular breeding programmes in the future.

本研究克隆了牦牛谷胱甘肽过氧化酶1GPX1基因的CDS区序列,分析了其核苷酸序列,并进行了系统发育分析.结果表明,牦牛GPX1基因CDS区全长618 bp,编码205个氨基酸;经与GenBank中其他物种GPX1基因CDS区比对,牦牛GPX1基因CDS区与普通牛和瘤牛完全一致,与水牛、绵羊和猪的序列一致性较高,与其他哺乳动物序列一致性较低.本研究为深入研究牦牛GPX1的生理功能提供了参考资料.

[目的]从分子水平上揭示青海省同德牦牛的母系遗传多样性、群体遗传结构和遗传背景.[方法]本研究采用PCR方法和扩增产物双向测序技术,对60头(32♂,28♀)同德牦牛mtDNA D-loop区序列进行了测定.经人工核实校对序列后,使用BioEdit、DnaSP、Ar-lequin和Network等生物信息学软件综合分析其母系遗传多样性、群体遗传结构及系统发育关系.[结果]同德牦牛mtDNA D-loop区序列长度在890-894 bp之间,排除12处插入/缺失后共检测到59处多态位点,其中单一多态位点有17处,简约信息位点42处;根据序列间核苷酸变异共确定了31种单倍型,其中H8为优势单倍型,单倍型多样度为0.935±0.023,核苷酸多样度为0.012±0.006.与青海其他牦牛品种(群体)(如高原、环湖、大通牦牛等)相比,同德牦牛单倍型多样度较高,表明其具有较为丰富的母系遗传多样性.使用MJ法(Me-dian-Joining)构建的网络关系图显示:同德牦牛31种单倍型分布在A、B、C、D和E 5种单倍型组中,且其可分为2大母系支系,表明同德牦牛拥有2个母系起源.[结论]同德牦牛群体具有较丰富的母系遗传多样性,由分布于2个母系遗传分支的5个单倍型组(即A、B、C、D和E)个体组成,具有2个母系起源.