Key Laboratory of Animal Genetics, Breeding and Reproduction of Ministry of Agriculture and Rural Affairs, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
Genes (Basel). 2021 Jan 18;12(1):109. doi: 10.3390/genes12010109.
Ovine litter size (LS) is an important trait showing variability within breeds. It remains largely unknown whether inbreeding depression on LS exists based on genomic homozygous regions, and whether the homozygous regions resulted from inbreeding are significantly associated with LS in sheep. We here reanalyze a set of single nucleotide polymorphism (SNP) chip of six breeds to characterize the patterns of runs of homozygosity (ROH), to evaluate inbreeding levels and inbreeding depressions on LS, and to identify candidate homozygous regions responsible for LS. Consequently, unique ROH patterns were observed among six sheep populations. Inbreeding depression on LS was only found in Hu sheep, where a significant reduction of 0.016, 0.02, and 0.02 per 1% elevated inbreeding F, F and the total inbreeding measure was observed, respectively. Nine significantly homozygous regions were found for LS in Hu sheep, where some promising genes for LS possibly via regulation of the development of oocytes (, , and ), fertilization (, , , , , and ), embryo implantation (, , and ) and development (, , , , and ), and reproductive health (, , , and ) were identified. These results from the present study would provide insights into the genetic management and complementary understandings of LS in sheep.
绵羊产羔数（LS）是一个重要的性状，在品种内存在变异性。目前尚不清楚基于基因组纯合区域是否存在 LS 的近交衰退，以及由近交引起的纯合区域是否与绵羊的 LS 显著相关。我们在此重新分析了六个品种的一组单核苷酸多态性（SNP）芯片，以描述纯合区域的连续模式，评估 LS 的近交水平和近交衰退，并确定负责 LS 的候选纯合区域。结果，在六个绵羊群体中观察到独特的 ROH 模式。LS 的近交衰退仅在湖羊中发现，其中分别观察到 LS 每增加 1%的近交 F、F 和总近交度量的显著减少 0.016、0.02 和 0.02。在湖羊中发现了 9 个与 LS 显著相关的纯合区域，其中一些与 LS 相关的有前途的基因可能通过调节卵母细胞的发育（、、和）、受精（、、、、、和）、胚胎着床（、、和）和发育（、、、、和）以及生殖健康（、、、和）。本研究的这些结果将为绵羊的遗传管理和 LS 的补充理解提供见解。
