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草业学报 ›› 2022, Vol. 31 ›› Issue (9): 183-194.DOI: 10.11686/cyxb2021464

• 研究论文 • 上一篇    

基于GBS简化基因组测序评估3个麦洼牦牛保种群的遗传结构研究

马士龙1,2(), 李小伟4, 李响1,2, 谢书琼2,3, 刘益丽1,2, 唐娇2,3, 江明锋1,2()   

  1. 1.西南民族大学畜牧兽医学院,四川 成都 610041
    2.青藏高原动物遗传育种资源保护与利用国家教育部重点实验室,四川 成都 610041
    3.西南民族大学青藏高原研究院,四川 成都 610041
    4.四川省龙日种畜场,四川 红原 624401
  • 收稿日期:2021-12-13 修回日期:2022-03-14 出版日期:2022-09-20 发布日期:2022-08-12
  • 通讯作者: 江明锋
  • 作者简介:Corresponding author. E-mail: mingfengjiang@vip.sina.com
    马士龙(1996-),男,河南驻马店人,在读硕士。E-mail: 1471879112@ qq.com
  • 基金资助:
    四川省重点研发项目(2021YFN0001);四川省科技计划项目(2021YFYZ0001)

Assessment of genetic structure of 3 Maiwa yak preserved populations based on genotyping-by-sequencing technology

Shi-long MA1,2(), Xiao-wei LI4, Xiang LI1,2, Shu-qiong XIE2,3, Yi-li LIU1,2, Jiao TANG2,3, Ming-feng JIANG1,2()   

  1. 1.College of Animal and Veterinary Medicine,Southwest Minzu University,Chengdu 610041,China
    2.Key Laboratory of Qinghai-Tibetan Plateau Animal Genetic Resource Reservation and Utilization of Ministry of Education,Chengdu 610041,China
    3.Institute of Qinghai-Tibetan Plateau,Southwest Minzu University,Chengdu 610041,China
    4.Longri Breeding Farm of Sichuan,Hongyuan 624401,China
  • Received:2021-12-13 Revised:2022-03-14 Online:2022-09-20 Published:2022-08-12
  • Contact: Ming-feng JIANG

摘要:

麦洼牦牛是青藏高原地区优良的乳肉兼用型牦牛品种,本研究旨在探究四川省龙日种畜场麦洼牦牛保种群的遗传多样性和遗传结构,评价3个不同保种群的保种效果并挖掘重要种质特性基因。对麦洼牦牛3个保种群粉嘴群(n=140)、全黑群(n=211)、弗洛群(n=55)进行GBS简化基因组测序,基于检测到的126122个单核苷酸多态性(SNPs)标记计算遗传统计量,结果表明,整个牦牛群的平均观测杂合度(Ho)和平均期望杂合度(He)为0.3038和0.3036,麦洼牦牛的遗传多样性较丰富。全黑群、粉嘴群、弗洛群的观测杂合度Ho分别为0.3029、0.3042、0.3044,近交系数Fis分别为0.0144、0.0152、0.0209,弗洛群和粉嘴群受人工选择的强度大于全黑群,较低的近交水平说明3个群的保种效果较好。Structure分析中全黑、弗洛群部分个体血缘较纯正,而其他个体血缘关系非常混杂;粉嘴群和全黑群的遗传分化系数(Fst)和遗传距离(DR)最大为0.03513、0.0358,结合系统进化树表明两者亲缘关系最远,有遗传分化趋势。利用Fst和π法对3个保种群进行选择信号分析,发现有104个受选择基因广泛参与生殖机能、免疫系统、胚胎发育、脂质代谢等条目以及生殖激素、内/外分泌、信号传递等通路,其中部分基因提示麦洼牦牛的繁殖、肉质、毛色性状以及应激反应得到了人工选择,如PPP3CCKCNMA1ROCK2GNAQMEF2CKIT等。现有的麦洼牦牛保种策略是可行的,研究结果为未来麦洼牦牛的保种选育和遗传改良提供了参考依据。

关键词: 麦洼牦牛, GBS, 遗传多样性, 遗传结构, 选择信号

Abstract:

The Maiwa yak, a breed of domestic yak, is an excellent yak strain for meat and milk production on the Qinghai-Tibetan Plateau. This study explored the genetic diversity and genetic structure of the Maiwa yak population in Longri Breeding Farm in Sichuan Province. A key aim was to identify genes important to defining germplasm categories and thereby evaluate the conservation status of three preserved populations. We used genotyping-by-sequencing (GBS) technology to categorize three preserved populations: The ‘pink mouth’ population (FZ) (n=140), the ‘full black’ population (QH) (n=211) and the ‘gray coat’ population (FL) (n=55). Analysis of the resulting sequences identified 126122 single nucleotide polymorphism (SNP) markers which were used to calculate genetic statistics such as observed heterozygosity (Ho), inbreeding coefficients (Fis), genetic differentiation index (Fst), and genetic distance (DR). The average observed heterozygosity values and average expected heterozygosity values (He) of the whole Maiwa yak population were 0.3038 and 0.3036. The genetic diversity of Maiwa yak was high. The Ho values of QH, FZ and FL were 0.3029, 0.3042, 0.3044, respectively, while the Fis values were 0.0144, 0.0152, 0.0209, respectively. The intensity of artificial selection of FL and FZ was greater than QH, and the lower inbreeding level showed that the conservation status of the three preserved populations was better in Longri Breeding Farm. Structure analysis showed that the pedigree of some individuals in QH and FL is pure, while the pedigree of other individuals is extremely mixed. The Fst and DR of FZ and QH populations were 0.03513 and 0.0358, respectively. The genetic distance between FZ and QH was the greatest and there was obvious genetic differentiation between them; This result was consistent with a constructed phylogenetic tree. In addition, we also performed a selective signal analysis of the three preserved populations using Fst and π methods. The 104 selected genes were involved in a wide range of metabolic processes, including reproductive function, the immune system, embryonic development, lipid metabolism and others, as well as signal transduction, reproductive hormone, endocrine/exocrine, and other signal transduction pathways. Some of them, such as PPP3CCKCNMA1ROCK2GNAQMEF2C, and KIT geneswere related to reproduction, meat quality, coat color traits and stress response of Maiwa yaks. In conclusion, the existing conservation strategy of Maiwa yak is tenable. The study provide genetic reference data for future conservation breeding and genetic improvement of Maiwa yak.

Key words: Maiwa yak, GBS, genetic diversity, genetic structure, selective signal