Abstract：
Environmental adaptation traits of indigenous African cattle are increasingly being investigated to respond to the need for sustainable livestock production in the context of unpredictable climatic changes. Several studies have highlighted genomic regions under positive selection probably associated with adaptation to environmental challenges (e.g. heat stress, trypanosomiasis, tick and tick-borne diseases). However, little attention has focused on pinpointing the candidate causative variant(s) controlling the traits. This review compiled information from 22 studies on signatures of positive selection in indigenous African cattle breeds to identify regions under positive selection. We highlight some key candidate genome regions and genes of relevance to the challenges of living in extreme environments (high temperature, high altitude, high infectious disease prevalence). They include candidate genes involved in biological pathways relating to innate and adaptive immunity (e.g. BoLAs, SPAG11, IL1RL2 and GFI1B), heat stress (e.g. HSPs, SOD1 and PRLH) and hypoxia responses (e.g. BDNF and INPP4A). Notably, the highest numbers of candidate regions are found on BTA3, BTA5 and BTA7. They overlap with genes playing roles in several biological functions and pathways. These include but are not limited to growth and feed intake, cell stability, protein stability and sweat gland development. This review may further guide targeted genome studies aiming to assess the importance of candidate causative mutations, within regulatory and protein-coding genome regions, to further understand the biological mechanisms underlying African cattle\'s unique adaption.
摘要：
在不可预测的气候变化的背景下，越来越多地研究非洲土著牛的环境适应特征，以应对可持续畜牧业生产的需求。几项研究强调了积极选择下的基因组区域，可能与适应环境挑战有关（例如，热应激，锥虫病,蜱和蜱传疾病)。然而,很少有人将注意力集中在确定控制性状的候选致病变异上。这篇评论收集了来自22项关于非洲土著牛品种阳性选择特征的研究的信息，以确定阳性选择区域。我们强调了一些与极端环境中生活挑战相关的关键候选基因组区域和基因（高温，高海拔,传染病患病率高)。它们包括参与与先天和适应性免疫相关的生物学途径的候选基因（例如，BoLAs，SPAG11,IL1RL2和GFI1B),热应力(例如HSPs，SOD1和PRLH）和缺氧反应（例如BDNF和INPP4A）。值得注意的是,在BTA3、BTA5和BTA7上发现了数量最多的候选区域。它们与在几种生物学功能和途径中发挥作用的基因重叠。这些包括但不限于生长和采食，细胞稳定性，蛋白质稳定性和汗腺发育。这篇综述可能会进一步指导靶向基因组研究，旨在评估候选致病突变的重要性。在调节和蛋白质编码基因组区域内，进一步了解非洲牛独特适应的生物学机制。
