DataSheet1_Analysis of World-Scale Mitochondrial DNA Reveals the Origin and Migration Route of East Asia Goats.xlsx

Despite much attention on the history of goat evolution, information on origin, demographic history, and expansion route remains controversial. To address these questions, we collected 4,189 published goat DNA sequences including 1,228 sequences from 57 breeds in China and 2,961 sequences including 193 goat breeds from 71 other countries and carried out an integrated analysis. We found goat breeds from South China had the highest genetic diversity of lineage B, and subclades B2 only were found in Southwest China, suggesting that lineage B (particularly, subclade B2) probably originated from Southwest China and its surrounding areas. In addition, in this study, we found that lineage A from South China also presented higher genetic diversity and earlier expansion time (10, 606 years ago), even earlier than breeds from the Middle East. Hence, we speculated that South China and surrounding areas were the origin of lineage B and also the transportation hub for lineage A spreading to North China and Southwest Asia. Furthermore, according to the analysis of correlation between genetic differentiation value λ1 and λ2 and geographical distance, we further confirmed two phases of migration in goat breeds of North China. These results will contribute to a better understanding of the origin and migration history of domestic goat.

尽管学界对山羊演化历史已有诸多关注，但有关其起源、种群历史与扩散路径的相关认知仍存在争议。为解答上述疑问，本研究收集了4189条已发表的山羊DNA序列：其中包含来自中国57个品种的1228条序列，以及来自其他71个国家的193个山羊品种的2961条序列，并开展了整合分析。本研究发现，中国南方的山羊品种在B谱系（lineage B）上具有最高的遗传多样性，且仅在中国西南地区发现了B2亚支（subclade B2），这表明B谱系（尤其是B2亚支）大概率起源于中国西南地区及其周边区域。此外，本研究还发现，中国南方的A谱系（lineage A）同样具备更高的遗传多样性，其扩张时间（10606年前）甚至早于中东地区的山羊品种。据此我们推测，中国南方及其周边区域既是B谱系的起源地，也是A谱系向北中国及西南亚传播的枢纽。此外，通过对遗传分化值λ1与λ2及地理距离之间的相关性分析，本研究进一步证实了中国北方山羊品种存在两阶段迁徙过程。上述研究结果将有助于更深入地认识家养山羊的起源与迁徙历史。