Abstract：
This study aimed to evaluate the genetic diversity and structure within the Dengchuan cattle population and effectively protect and utilize their germplasm resources. Herein, the single-nucleotide polymorphisms (SNPs) of 100 Dengchuan cattle (46 bulls and 54 cows) were determined using the GGP Bovine 100K SNP Beadchip. The results showed that among the Dengchuan cattle, a total of 101,220 SNPs were detected, and there were 83,534 SNPs that passed quality control, of which 85.7% were polymorphic. The average genetic distance based on identity-by-state (IBS) within the conservation population of Dengchuan cattle was 0.26 ± 0.02. A total of 3,999 genome-length runs of homozygosity (ROHs) were detected in the Dengchuan cattle, with ROH lengths primarily concentrated in the range of 1-5 Mb, accounting for 87.02% of the total. The average inbreeding coefficient based on ROHs was 4.6%, within the conservation population of Dengchuan cattle, whereas it was 4.9% for bulls, and the Wright inbreeding coefficient (FIS) value was 2.4%, demonstrating a low level of inbreeding within the Dengchuan cattle population. Based on neighbor-joining tree analysis, the Dengchuan cattle could be divided into 16 families. In summary, the conservation population of Dengchuan cattle displays relatively abundant diversity and a moderate genetic relationship. Inbreeding was observed among a few individuals, but the overall inbreeding level of the population remained low. It is important to maintain this low level of inbreeding when introducing purebred bloodlines to expand the core group. This approach will ensure the long-term conservation of Dengchuan cattle germplasm resources and prevent loss of genetic diversity.
摘要：
本研究旨在评价登川黄牛群体的遗传多样性和结构，有效保护和利用其种质资源。在这里，使用GGP牛100KSNPBeadchip测定了100头登川牛（46头公牛和54头母牛）的单核苷酸多态性（SNP）。结果表明,在登川黄牛中,共检测到101,220个SNP,有83,534个SNP通过了质量控制，其中85.7%是多态的。登川牛保护种群内基于国家身份（IBS）的平均遗传距离为0.26±0.02。在登川牛中共检测到3,999个基因组长度的纯合性（ROHs），ROH长度主要集中在1-5Mb的范围内，占总数的87.02%。基于ROHs的平均近交系数为4.6%，在登川牛的保护种群中，而多头为4.9%，赖特近亲繁殖系数(FIS)值为2.4%，显示登川牛种群内近亲繁殖水平较低。基于邻居连接树分析，邓川牛可以分为16个家庭。总之,登川牛的保护种群表现出相对丰富的多样性和中等的亲缘关系。在少数个体中观察到近亲繁殖，但是总体近亲繁殖水平仍然很低。在引入纯种血统以扩大核心群体时，保持这种低水平的近亲繁殖很重要。这种方法将确保登川牛种质资源的长期保存并防止遗传多样性的丧失。
