Abstract

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.

摘要

野牦牛 ( Bos mutus ) 是青藏高原 (QTP) 上的脆弱牛种。到目前为止，大多数关于野牦牛分子遗传多样性的研究都集中在基于少量样本的常染色体和mtDNA变异上。本研究分析了84个D-loop和24个完整的野生牦牛有丝分裂基因组序列，以进一步全面探索其母系遗传多样性和谱系组成。同时，利用 6 个牦牛 Y 特异性多态性标记（即SRY4、USP9Y、UTY19、AMELY3、OFD1Y10和INRA189)，我们评估了基于八头野牦牛的父系遗传多样性和谱系组成。我们的研究结果表明，野牦牛表现出丰富的母体遗传多样性，在 D 环和整个有丝分裂基因组序列中的单倍型多样性分别为 0.9621 ± 0.0078 和 0.9928 ± 0.0144。野生牦牛的母体系统发育分析揭示了三个确定的谱系（mt-I、mt-II 和 mt-III）。同样，在野牦牛中观察到丰富的父本遗传多样性，Y 单倍型多样性 (Hd) 为 0.8214 ± 0.1007。在父本系统发育分析中鉴定出具有四种 Y 单倍型 (yH1-yH4) 的两个 Y 单倍群 (Y1 和 Y2)，表明野牦牛属于两个父本谱系。