Meadows Jennifer R S, Cemal Ibrahim, Karaca Orhan, Gootwine Elisha, Kijas James W
CSIRO Livestock Industries, St. Lucia, Brisbane 4067, Queensland, Australia.
Genetics. 2007 Mar;175(3):1371-9. doi: 10.1534/genetics.106.068353. Epub 2006 Dec 28.
Archaeozoological evidence indicates that sheep were first domesticated in the Fertile Crescent. To search for DNA sequence diversity arising from previously undetected domestication events, this survey examined nine breeds of sheep from modern-day Turkey and Israel. A total of 2027 bp of mitochondrial DNA (mtDNA) sequence from 197 sheep revealed a total of 85 haplotypes and a high level of genetic diversity. Six individuals carried three haplotypes, which clustered separately from the known ovine mtDNA lineages A, B, and C. Analysis of genetic distance, mismatch distribution, and comparisons with wild sheep confirmed that these represent two additional mtDNA lineages denoted D and E. The two haplogroup E sequences were found to link the previously identified groups A and C. The single haplogroup D sequence branched with the eastern mouflon (Ovis orientalis), urial (O. vignei), and argali (O. ammon) sheep. High sequence diversity (K = 1.86%, haplogroup D and O. orientalis) indicates that the wild progenitor of this domestic lineage remains unresolved. The identification in this study of evidence for additional domestication events adds to the emerging view that sheep were recruited from wild populations multiple times in the same way as for other livestock species such as goat, cattle, and pig.
考古动物学证据表明,绵羊最初是在新月沃地被驯化的。为了寻找先前未被发现的驯化事件所产生的DNA序列多样性,这项调查研究了来自现代土耳其和以色列的九个绵羊品种。从197只绵羊中获得的总共2027 bp的线粒体DNA(mtDNA)序列揭示了总共85个单倍型和高水平的遗传多样性。有六只个体携带三种单倍型,它们与已知的绵羊mtDNA谱系A、B和C分开聚类。对遗传距离、错配分布的分析以及与野生绵羊的比较证实,这些代表了另外两个mtDNA谱系,分别命名为D和E。发现两个E单倍群序列将先前确定的A和C组联系起来。单个D单倍群序列与东高加索羱羊(Ovis orientalis)、乌利亚羊(O. vignei)和盘羊(O. ammon)绵羊分支。高序列多样性(K = 1.86%,D单倍群和东高加索羱羊)表明这个家养谱系的野生祖先仍然不确定。本研究中对额外驯化事件证据的鉴定,进一步支持了这样一种新出现的观点,即绵羊与山羊、牛和猪等其他家畜物种一样,多次从野生种群中被驯化。