| 摘要: |
| 为从分子水平上对青海省果洛藏族自治州牦牛遗传资源进行系统评估，分析其母系遗传多样性、群体遗传结构和群体遗传分化，本研究对甘德、班玛、久治和玛多牦牛群体共152头个体进行线粒体DNA（mtDNA）D-loop区测序，并从GenBank下载已公布的37条达日牦牛和32条玛沁牦牛的相应序列，对这6个牦牛群体mtDNA D-loop序列进行综合分析。结果表明：1）221条牦牛mtDNA D-loop序列（636~638 bp）比对分析共检测出57个变异位点，包括8个单一多态位点和49个简约信息位点。根据D-loop序列间核苷酸变异共确定了45种单倍型，其中班玛、达日、甘德、久治、玛多、玛沁牦牛群体分别拥有1、6、5、4、7、6种特有单倍型。2）6个牦牛群体总的单倍型多样度和核苷酸多样度为0.901和0.014，表明其母系遗传多样性丰富。其中，甘德牦牛的单倍型多样度最高（Hd=0.951），久治牦牛的单倍型多样度最低（Hd=0.818）。3）遗传分化和基因流分析表明，除久治牦牛与班玛、甘德、玛沁牦牛群体间分化程度均呈中等遗传分化水平（0.05≤FST<0.15），基因交流相对贫乏外，其他牦牛群体间FST值较小（0<FST<0.05），分化程度弱，基因交流相对频繁。4）聚类分析表明久治、甘德、班玛3个牦牛群体间亲缘关系较近，而玛多、玛沁、达日3个牦牛群体间亲缘关系较近。5）系统发育分析显示6个牦牛群体中除久治牦牛由3个母系遗传支系（即Mt-Ⅰ、Mt-Ⅱ和Mt-Ⅲ）组成外，其他群体均由Mt-Ⅰ和Mt-Ⅱ 2个母系支系组成，推测果洛藏族自治州中久治牦牛群体有3个母系起源，其他牦牛群体均有2个母系起源。综上，青海省果洛藏族自治州6个牦牛群体均拥有特殊的母系遗传信息且母系遗传多样性较为丰富；各牦牛群体间遗传分化程度整体较弱；久治、甘德和班玛3个牦牛群体间亲缘关系较近，而玛多、玛沁和达日3个牦牛群体间亲缘关系较近；除久治牦牛群体有3个母系起源外，其他牦牛群体均有2个母系起源。本研究为青海省果洛藏族自治州牦牛遗传资源的合理保护和开发利用提供了理论基础。 |
| 关键词: 牦牛 mtDNA D-loop区 遗传多样性 遗传分化 群体结构 系统发育 |
| DOI：10.11841/j.issn.1007-4333.2024.08.11 |
| 投稿时间：2023-10-09 |
| 基金项目:青海省“昆仑英才·高端创新创业人才”计划（领军人才）项目和畜禽遗传资源普查项目 |
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| Exploring maternal genetic diversity and population genetic structure of yak genetic resources in Golog Prefecture, Qinghai, China based on mtDNA D-loop sequence variations |
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CAO Ping1, MEI Sa2, CHEN Shengmei1, LI Hongkang3, GUO Weixing1, LI Ruizhe1, DA Sang4, CAI Jia5, MO Yanxin6, GUANQUE Zhaxi6, ZHONG Ga4, LI Wenhao1, LIU Shujie1, CUI Hongwei7, MA Zhijie1*
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| (1.Academy of Animal Science and Veterinary Medicine, Qinghai University/Plateau Livestock Genetic Resources Protection and Innovative Utilization Key Laboratory of Qinghai Province/ Key Laboratory of Livestock and Poultry Genetics and Breeding on the Qinghai-Tibet Plateau, Xining 810016, China;2.Station of Animal Husbandry and Veterinary, Banma County of Golog Prefecture in Qinghai Province, Golog 814399, China;3.Qinghai Yak Breeding Extension Service Center, Xining 810102, China;4.Station of Animal Husbandry and Veterinary, Suohurima Town of Jiuzhi County of Golog Prefecture in Qinghai Province, Golog 814499, China;5.Laze Ecological Livestock Specialized Cooperative, Cuorou Village of Huashixia Town of Maduo County of Golog Prefecture in Qinghai Province, Golog 813500, China;6.Qinghai Livestock and Poultry Genetic Resources Protection and Utilization Center, Xining 810016, China;7.Bureau of Agriculture and Livestock, Science and Technology of Golog Prefecture in Qinghai Province, Golog 814100, China) |
| Abstract: |
| To systematically evaluate the maternal genetic diversity， population genetic structure and population genetic differentiation of the yak genetic resources in Golog Tibetan Autonomous Prefecture of Qinghai Province， China at the molecular level， a total of 152 yaks from Gande， Banma， Jiuzhi， and Maduo Counties were collected and the corresponding mtDNA D-loop sequences were sequenced. The six yak populations were comprehensively analyzed after downloading 37 and 32 reported mtDNA D-loop sequences of Dari and Maqin yak populations from Genbank. The results showed that： 1） 57 polymorphic sites were detected in 221 mtDNA D-loop （636- 638 bp） sequences of six yak populations， including 8 single polymorphic sites and 49 parsimony informative sites. A total of 45 haplotypes were identified based on nucleotide variations， among which 1， 6， 5， 4， 7， 6 specific haplotypes were detected in Banma， Dari， Gande， Jiuzhi， Maduo， and Maqin yak populations， respectively. 2）The haplotype diversity and nucleotide diversity of the six yak populations were 0.901 and 0.014， indicating abundant maternal genetic diversity in these yak populations. Among them， the highest haplotype diversity was found in the Gande yak population （Hd=0.951） and the lowest in the Jiuzhi yak population （Hd=0.818）. 3）Analysis of genetic differentiation and gene flow showed moderate genetic differentiation （0.05≤FST<0.15） and poor gene exchange between Jiuzhi yak population and Banma， Gande， and Maqin yak populations respectively. However， the FST values among other yak populations were lower （0<FST<0.05） and had a low genetic differentiation， indicating gene exchange was relatively frequent. 4）The clustering of Jiuzhi， Gande， and Banma yak populations was closer， while the clustering of Maduo， Maqin， and Dari yak populations was also closer. 5）Phylogenetic analysis showed that among the six yak populations， except for the Jiuzhi yak population， which was composed of three maternal lineages （i.e.， Mt-Ⅰ， Mt-Ⅱ， and Mt-Ⅲ）， the other yak populations were composed of two maternal lineages （Mt-Ⅰ and Mt-Ⅱ）. It was speculated that Jiuzhi yak population has three maternal origins， and the other yak populations have two maternal origins. In summary， the six yak populations in Golog Tibetan Autonomous Prefecture all had unique maternal genetic information and relatively rich maternal genetic diversity. The overall genetic differentiation among the 6 yak populations was very weak. The clustering of Jiuzhi， Gande， and Banma yak populations was closer， while the clustering of Maduo， Maqin， and Dari yak populations was closer. Except for the Jiuzhi yak population with three maternal origins， the other yak populations had two maternal origins. This study will provide a theoretical basis for further reasonable protection， development， and utilization of yak genetic resources in Golog Tibetan Autonomous Prefecture of Qinghai Province. |
| Key words: yak mtDNA D-loop region genetic diversity genetic differentiation population structure phylogeny |
