Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden.
Department of Animal Production and Technology, Bahir Dar University, Bahir Dar, Ethiopia.
PLoS One. 2019 Apr 19;14(4):e0214843. doi: 10.1371/journal.pone.0214843. eCollection 2019.
Indigenous goats make significant contributions to Cameroon's national and local economy, but little effort has been devoted to identifying the populations. Here, we assessed the genetic diversity and demographic dynamics of Cameroon goat populations using mitochondrial DNA (two populations) and autosomal markers (four populations) generated with the Caprine 50K SNP chip. To infer genetic relationships at continental and global level, genotype data on six goat populations from Ethiopia and one population each from Egypt, Morocco, Iran, and China were included in the analysis. The mtDNA analysis revealed 83 haplotypes, all belonging to haplogroup A, in Cameroon goats. Four haplotypes were shared between goats found in Cameroon, Mozambique, Namibia, Zimbabwe, Kenya, and Ethiopia. Analysis of autosomal SNPs in Cameroon goats revealed the lowest HO (0.335±0.13) and HE (0.352±0.15) in the North-west Highland and Central Highland populations, respectively. Overall, the highest HO (0.401±0.12) and HE (0.422±0.12) were found for Barki and Iranian goats, respectively. Barki goats had the highest average MAF, while Central Highland Cameroon goats had the lowest. Overall, Cameroon goats demonstrated high FIS. AMOVA revealed that 13.29% of the variation was explained by genetic differences between the six population groups. Low average FST (0.01) suggests intermixing among Cameroon goats. All measures indicated that Cameroon goats are closer to Moroccan goats than to other goat populations. PCA and STRUCTURE analyses poorly differentiated the Cameroon goats, as did genetic distance, Neighbor-Net network, and neighbor-joining tree analyses. The haplotype analysis of mtDNA showed the initial dispersion of goats to Cameroon and central Africa from north-east Africa following the Nile Delta. Whereas, the approximate Bayesian computation indicated Cameroon goats were separated from Moroccan goats after 506 generations in later times (~1518 YA), as supported by the phylogenetic net-work and admixture outputs. Overall, indigenous goats in Cameroon show weak phylogenetic structure, suggesting either extensive intermixing.
本地山羊对喀麦隆的国家和地方经济做出了重大贡献，但在确定种群方面几乎没有做出努力。在这里，我们使用线粒体 DNA（两个群体）和基于 Caprine 50K SNP 芯片的常染色体标记（四个群体）评估了喀麦隆山羊种群的遗传多样性和种群动态。为了在大陆和全球水平上推断遗传关系，我们将来自埃塞俄比亚的六个山羊群体的基因型数据以及来自埃及、摩洛哥、伊朗和中国的每个群体的一个数据纳入分析。线粒体 DNA 分析显示，喀麦隆山羊的 83 个单倍型均属于 A 单倍群。喀麦隆、莫桑比克、纳米比亚、津巴布韦、肯尼亚和埃塞俄比亚的山羊共享 4 个单倍型。对喀麦隆山羊常染色体 SNP 的分析显示，西北高地和中央高地群体的 HO（0.335±0.13）和 HE（0.352±0.15）分别最低。总体而言，Barki 和伊朗山羊的 HO（0.401±0.12）和 HE（0.422±0.12）最高。Barki 山羊的平均 MAF 最高，而中央高地喀麦隆山羊的平均 MAF 最低。总体而言，喀麦隆山羊表现出较高的 FIS。AMOVA 表明，6 个群体间的遗传差异解释了 13.29%的变异。低平均 FST（0.01）表明喀麦隆山羊之间存在混合。所有指标均表明，喀麦隆山羊与摩洛哥山羊的关系比与其他山羊种群的关系更密切。PCA 和 STRUCTURE 分析未能很好地区分喀麦隆山羊，遗传距离、Neighbor-Net 网络和邻接树分析也是如此。线粒体 DNA 的单倍型分析表明，山羊最初是从东北非沿着尼罗河三角洲扩散到喀麦隆和中非。而近似贝叶斯计算表明，喀麦隆山羊在大约 1518 年前（506 代之后）与摩洛哥山羊分离，这一结果得到了系统发育网络和混合输出的支持。总体而言，喀麦隆的本地山羊显示出较弱的系统发育结构，这表明它们之间存在广泛的混合。
