Genetic homogeneity of North-African goats

North Africa represents a rich and early reservoir of goat genetic diversity, from which the main African breeds have been derived. In this study, the genetic diversity of four indigenous Algerian goat breeds (i.e., Arabia, Makatia, M’Zabite and Kabyle, with n = 12 for each breed) has been investigated for the first time by genome-wide SNP genotyping; moreover in a broader context, genetic structuration of Algerian and Moroccan goats was explored (via FST, MDS, STRUCTURE, FineSTRUCTURE, BAPS, sPCA and DAPC analyses). At national level, the study revealed high level of genetic diversity and a significant phenomenon of admixture affecting all the Algerian breeds. At broader scale, clear global genetic homogeneity appeared considering both Algerian and Moroccan stocks. Indeed, genetic structuration was almost nonexistent among Arabia (from Algeria), Draa, Black and Nord (from Morocco), while the ancestral Kabyle and M’Zabite breeds, reared by Berber peoples, showed genetic distinctness. The study highlighted the threat to the Maghrebin stock, probably induced by unsupervised cross-breeding practices which have intensified in recent centuries. Moreover, it underlined the necessity to deepen our understanding of the genetic resources represented by the resilient North-African goat stock.北非拥有丰富且古老的山羊遗传多样性资源，非洲主要山羊品种均源自于此。本研究首次采用全基因组单核苷酸多态性(Single Nucleotide Polymorphism, SNP)基因分型技术，对4个阿尔及利亚本土山羊品种（阿拉伯山羊、马卡蒂亚山羊、姆扎比特山羊与卡比尔山羊，每个品种样本量n=12）的遗传多样性展开探究；同时在更大尺度下，通过FST、MDS、STRUCTURE、FineSTRUCTURE、BAPS、sPCA及DAPC分析，探究了阿尔及利亚与摩洛哥山羊的遗传结构。在国家层面，本研究揭示阿尔及利亚所有山羊品种均具有高水平遗传多样性，且存在显著的基因混合现象。在更大区域尺度上，阿尔及利亚与摩洛哥山羊种群整体呈现出显著的遗传均质性。具体而言，阿尔及利亚的阿拉伯山羊，以及摩洛哥的德拉(Draa)山羊、黑山羊与北部(Nord)山羊种群之间几乎不存在遗传结构分化；而由柏柏尔人饲养的古老卡比尔山羊与姆扎比特山羊则表现出显著的遗传特异性。本研究同时指出，近几个世纪以来无序杂交繁育行为加剧，对马格里布山羊种群构成了威胁。此外，本研究强调亟需深化对抗逆性强的北非山羊种群所代表的遗传资源的认知。