Institute of Genetics, Vetsuisse Faculty, University of Bern, 3001 Bern, Switzerland.
Institute of Biotechnology, Gulab Devi Educational Complex, Lahore 54000, Pakistan.
Genes (Basel). 2020 Feb 5;11(2):168. doi: 10.3390/genes11020168.
Goat domestication and human selection for valued traits have formed diverse breeds with characteristic phenotypes. This process led to the fixation of causative genetic variants controlling breed-specific traits within regions of reduced genetic diversity-so-called "selection signatures". We previously reported an analysis of selection signatures based on pooled whole-genome sequencing data of 20 goat breeds and bezoar goats. In the present study, we reanalyzed the data and focused on a subset of eight Pakistani goat breeds (Angora, Barbari, Beetal, Dera Din Panah, Kamori, Nachi, Pahari, Teddy). We identified 749 selection signatures based on reduced heterozygosity in these breeds. A search for signatures that are shared across large-sized goat breeds revealed that five medium-to-large-sized Pakistani goat breeds had a common selection signature on chromosome 6 in a region harboring the gene, which has been shown to modulate height or body size in several mammalian species. Fine-mapping of the region confirmed that all five goat breeds with the selection signature were nearly fixed for the same haplotype in a ~191 kb region spanning positions 37,747,447-37,938,449. From the pool sequencing data, we identified a frame-shifting single base insertion into an isoform-specific exon of as a potential candidate causal variant mediating the size-increasing effect. If this preliminary result can be confirmed in independent replication studies, genotyping of this variant might be used to improve breeding programs and the selection for stature in goats.
家羊的驯化和人类对有价值特征的选择形成了具有特征表型的多样化品种。这一过程导致了控制品种特异性特征的因果遗传变异在遗传多样性减少的区域内固定下来，即所谓的“选择特征”。我们之前根据 20 个绵羊品种和结石羊的全基因组测序数据进行了选择特征的分析。在本研究中，我们重新分析了数据，并集中研究了 8 个巴基斯坦绵羊品种（安哥拉羊、巴巴里羊、贝塔尔羊、德拉迪纳潘阿羊、卡莫利羊、纳奇羊、帕哈里羊、泰迪羊）的一个子集。我们在这些品种中发现了基于杂合性降低的 749 个选择特征。在大型绵羊品种中寻找共享的特征表明，5 个中等到大型的巴基斯坦绵羊品种在包含 基因的染色体 6 上有一个共同的选择特征，该基因已被证明在几个哺乳动物物种中调节身高或体型。该区域的精细映射证实，所有具有选择特征的 5 个绵羊品种在跨越位置 37,747,447-37,938,449 的约 191kb 区域内，几乎都固定了相同的单倍型。从池测序数据中，我们鉴定出一个移框单碱基插入到 基因的一个同种型特异性外显子中，这可能是一个潜在的候选因果变异，介导了大小增加的效应。如果这一初步结果能够在独立的复制研究中得到证实，对该变异的基因分型可能用于改善绵羊的育种计划和体型选择。
