BACKGROUND Indigenous domestic chicken represents a major source of protein for agricultural communities around the world. In the Middle East and Africa, they are adapted to hot dry and semi-dry areas, in contrast to their wild ancestor, the Red junglefowl, which lives in humid and sub-humid tropical areas. Indigenous populations are declining following increased demand for poultry meat and eggs, favouring the more productive exotic commercial breeds. In this paper, using the D-loop of mitochondrial DNA as a maternally inherited genetic marker, we address the question of the origin and dispersal routes of domestic chicken of the Middle East (Iraq and Saudi Arabia), the northern part of the African continent (Algeria and Libya) and the Horn of Africa (Ethiopia). RESULTS The analysis of the mtDNA D-loop of 706 chicken samples from Iraq (n = 107), Saudi Arabia (n = 185), Algeria (n = 88), Libya (n = 23), Ethiopia (n = 211) and Pakistan (n = 92) show the presence of five haplogroups (A, B, C, D and E), suggesting more than one maternal origin for the studied populations. Haplogroup E, which occurred in 625 samples, was the most frequent in all countries. This haplogroup most likely originates from the Indian subcontinent and probably migrated following a terrestrial route to these different countries. Haplotypes belonging to haplogroup D were present in all countries except Algeria and Libya, it is likely a legacy of the Indian Ocean maritime trading network. Haplogroup A was present in all countries and may be of commercial origin. Haplogroup B was found only in Ethiopia. Haplogroup C was only detected in the South-Western region of Saudi Arabia and in Ethiopia. CONCLUSION The results support a major influence of the Indian subcontinent on the maternal diversity of the today's chicken populations examined here. Most of the diversity occurs within rather than between populations. This lack of phylogeographic signal agrees with both ancient and more recent trading networks having shaped the modern-day diversity of indigenous chicken across populations and countries.

中文翻译：

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本地家养鸡的母体起源于中东，北部和非洲之角。

背景技术本土的家禽代表了全世界农业社区的主要蛋白质来源。在中东和非洲，它们适应于炎热干燥和半干旱地区，与它们的野生祖先红色丛林鸟相反，后者生活在潮湿和半湿润的热带地区。随着对家禽肉和蛋的需求增加，土著人口正在减少，这有利于生产力更高的外来商品品种。在本文中，利用线粒体DNA的D环作为母系遗传标记，我们解决了非洲大陆北部中东（伊拉克和沙特阿拉伯）的家养鸡的起源和传播途径问题（阿尔及利亚和利比亚）和非洲之角（埃塞俄比亚）。结果分析了来自伊拉克（n = 107）的706个鸡样品的mtDNA D环，沙特阿拉伯（n = 185），阿尔及利亚（n = 88），利比亚（n = 23），埃塞俄比亚（n = 211）和巴基斯坦（n = 92）显示存在五个单倍群（A，B，C，D和E），表明所研究人群有多个产妇来源。在625个样本中出现的Haplogroup E在所有国家中是最常见的。该单倍群很可能起源于印度次大陆，并可能通过陆地路线迁移到这些不同的国家。除阿尔及利亚和利比亚外，所有国家都存在属于单倍群D的单倍型，这很可能是印度洋海上贸易网络的遗产。单倍群A存在于所有国家，可能是商业来源。仅在埃塞俄比亚发现了单倍群B。仅在沙特阿拉伯的西南地区和埃塞俄比亚发现了单倍群C。结论结果支持了印度次大陆对今天调查的当今鸡种群的母体多样性的重大影响。大多数多样性发生在种群内部而不是种群之间。缺乏植物地理学的信号与古老的和较新的贸易网络​​相吻合，这些贸易网络塑造了跨种群和跨国家的现代本土鸡肉的现代多样性。