Taye Mengistie, Lee Wonseok, Caetano-Anolles Kelsey, Dessie Tadelle, Hanotte Olivier, Mwai Okeyo Ally, Kemp Stephen, Cho Seoae, Oh Sung Jong, Lee Hak-Kyo, Kim Heebal
Department of Agricultural Biotechnology and Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, Korea.
College of Agriculture and Environmental Sciences, Bahir Dar University, Bahir Dar, Ethiopia.
Anim Sci J. 2017 Dec;88(12):1889-1901. doi: 10.1111/asj.12851. Epub 2017 Jul 27.
As African indigenous cattle evolved in a hot tropical climate, they have developed an inherent thermotolerance; survival mechanisms include a light-colored and shiny coat, increased sweating, and cellular and molecular mechanisms to cope with high environmental temperature. Here, we report the positive selection signature of genes in African cattle breeds which contribute for their heat tolerance mechanisms. We compared the genomes of five indigenous African cattle breeds with the genomes of four commercial cattle breeds using cross-population composite likelihood ratio (XP-CLR) and cross-population extended haplotype homozygosity (XP-EHH) statistical methods. We identified 296 (XP-EHH) and 327 (XP-CLR) positively selected genes. Gene ontology analysis resulted in 41 biological process terms and six Kyoto Encyclopedia of Genes and Genomes pathways. Several genes and pathways were found to be involved in oxidative stress response, osmotic stress response, heat shock response, hair and skin properties, sweat gland development and sweating, feed intake and metabolism, and reproduction functions. The genes and pathways identified directly or indirectly contribute to the superior heat tolerance mechanisms in African cattle populations. The result will improve our understanding of the biological mechanisms of heat tolerance in African cattle breeds and opens an avenue for further study.
由于非洲本土牛在炎热的热带气候中进化，它们形成了固有的耐热性；生存机制包括浅色且有光泽的皮毛、增加出汗，以及应对高环境温度的细胞和分子机制。在此，我们报告了非洲牛品种中有助于其耐热机制的基因的正选择特征。我们使用跨群体复合似然比（XP-CLR）和跨群体扩展单倍型纯合性（XP-EHH）统计方法，将五个非洲本土牛品种的基因组与四个商业牛品种的基因组进行了比较。我们鉴定出296个（XP-EHH）和327个（XP-CLR）正选择基因。基因本体分析产生了41个生物学过程术语和六个京都基因与基因组百科全书途径。发现几个基因和途径参与氧化应激反应、渗透应激反应、热休克反应、毛发和皮肤特性、汗腺发育和出汗、采食量和代谢以及繁殖功能。所鉴定的基因和途径直接或间接地促成了非洲牛群体卓越的耐热机制。该结果将增进我们对非洲牛品种耐热生物学机制的理解，并为进一步研究开辟一条途径。
