Chebii Vivien J, Oyola Samuel O, Kotze Antoinette, Domelevo Entfellner Jean-Baka, Musembi Mutuku J, Agaba Morris
School of Life Science and Bioengineering, Nelson Mandela Africa Institution of Science and Technology, P.O. Box 447, Arusha 23306, Tanzania.
Biosciences Eastern and Central Africa-International Livestock Research Institute (BecA-ILRI) Hub, P.O. Box 30709, Nairobi 00100, Kenya.
Animals (Basel). 2020 Nov 22;10(11):2181. doi: 10.3390/ani10112181.
The domestic goat () is an important livestock species with a geographic range spanning all continents, including arid and semi-arid regions of Africa and Asia. The Nubian ibex (), a wild relative of the domestic goat inhabiting the hot deserts of Northern Africa and the Arabian Peninsula, is well-adapted to challenging environments in hot deserts characterized by intense solar radiation, thermal extremes, and scarce water resources. The economic importance of . breeds, as well as the current trends of global warming, highlights the need to understand the genetic basis of adaptation of . to the desert environments. In this study, the genome of a . individual was sequenced at an average of 37x coverage. Positively selected genes were identified by comparing protein-coding DNA sequences of . and related species using dN/dS statistics. A total of twenty-two positively selected genes involved in diverse biological functions such as immune response, protein ubiquitination, olfactory transduction, and visual development were identified. In total, three of the twenty-two positively selected genes are involved in skin barrier development and function (ATP binding cassette subfamily A member 12, Achaete-scute family bHLH transcription factor 4, and UV stimulated scaffold protein A), suggesting that . has evolved skin protection strategies against the damaging solar radiations that prevail in deserts. The positive selection signatures identified here provide new insights into the potential adaptive mechanisms to hot deserts in . .
家山羊（）是一种重要的家畜物种，其地理分布范围跨越各大洲，包括非洲和亚洲的干旱及半干旱地区。努比亚北山羊（）是家山羊的野生近亲，栖息于北非的炎热沙漠和阿拉伯半岛，能很好地适应炎热沙漠中具有强烈太阳辐射、极端温度和稀缺水资源的挑战性环境。家山羊品种的经济重要性以及全球变暖的当前趋势，凸显了了解家山羊适应沙漠环境的遗传基础的必要性。在本研究中，对一只家山羊个体的基因组进行了测序，平均覆盖度为37倍。通过使用dN/dS统计量比较家山羊和相关物种的蛋白质编码DNA序列，鉴定出了正选择基因。共鉴定出22个参与多种生物学功能的正选择基因，如免疫反应、蛋白质泛素化、嗅觉转导和视觉发育。在这22个正选择基因中，总共有3个基因参与皮肤屏障的发育和功能（ATP结合盒亚家族A成员12、achaete - scute家族bHLH转录因子4和紫外线刺激支架蛋白A），这表明家山羊已经进化出针对沙漠中普遍存在的有害太阳辐射的皮肤保护策略。此处鉴定出的正选择特征为家山羊对炎热沙漠的潜在适应性机制提供了新的见解。
