Genomic analysis of indigenous goats in Southwest Asia reveals evidence of ancient adaptive introgression related to desert climate

Understanding how evolutionary pressures related to climate change have shaped the current genetic background of domestic animals is a fundamental pursuit of biology. Here, we generated whole-genome sequencing data from native goat populations in Iraq and Pakistan. Combined with previously published data on modern, ancient (Late Neolithic to Medieval periods), and wild Capra species worldwide, we explored the genetic population structure, ancestry components, and signatures of natural positive selection in native goat populations in Southwest Asia (SWA). Results revealed that the genetic structure of SWA goats was deeply influenced by gene flow from the eastern Mediterranean during the Chalcolithic period, which may reflect adaptation to gradual warming and aridity in the region. Furthermore, comparative genomic analysis revealed adaptive introgression of the KITLG locus from the Nubian ibex ( C.nubiana) into African and SWA goats. The frequency of the selected allele at this locus was significantly higher among goat populations located near northeastern Africa. These results provide new insights into the genetic composition and history of goat populations in the SWA region.气候变化带来的进化压力如何塑造目前家养动物的遗传成分，是生物学领域一个重要的科学问题。该研究对伊拉克和巴基斯坦的地方山羊品种进行了全基因组重测序，并结合全球范围内的已发表古代和现代基因组数据，揭示了西南亚地方山羊品种的遗传结构、祖先成分和自然选择等特征。我们的研究结果表明，西南亚山羊的遗传结构受到来自红铜时期地中海东部山羊群体基因流的影响较大，这一时期的基因流可能反映了西南亚山羊对该地区逐渐温暖、干燥气候的适应。此外，比较基因组分析揭示了 KITLG基因座位中存在从努比亚北山羊 ( Capranubiana) 到非洲和西南亚山羊的适应性渗入。在靠近非洲东北部的山羊群体中，渗入型等位基因的频率明显更高。上述结果对西南亚地区山羊群体的遗传组成和演化历史提供了新的见解。.