CSIRO Livestock Industries, St Lucia, Queensland, Australia.
Heredity (Edinb). 2011 Apr;106(4):700-6. doi: 10.1038/hdy.2010.122. Epub 2010 Oct 13.
Five haplogroups have been identified in domestic sheep through global surveys of mitochondrial (mt) sequence variation, however these group classifications are often based on small fragments of the complete mtDNA sequence; partial control region or the cytochrome B gene. This study presents the complete mitogenome from representatives of each haplogroup identified in domestic sheep, plus a sample of their wild relatives. Comparison of the sequence successfully resolved the relationships between each haplogroup and provided insight into the relationship with wild sheep. The five haplogroups were characterised as branching independently, a radiation that shared a common ancestor 920,000 ± 190,000 years ago based on protein coding sequence. The utility of various mtDNA components to inform the true relationship between sheep was also examined with Bayesian, maximum likelihood and partitioned Bremmer support analyses. The control region was found to be the mtDNA component, which contributed the highest amount of support to the tree generated using the complete data set. This study provides the nucleus of a mtDNA mitogenome panel, which can be used to assess additional mitogenomes and serve as a reference set to evaluate small fragments of the mtDNA.
通过对全球线粒体 (mt) 序列变异的调查，已经在绵羊中鉴定出了五个单倍群，然而这些群体分类通常是基于 mtDNA 序列的小片段；部分控制区或细胞色素 B 基因。本研究从绵羊中鉴定出的每个单倍群的代表中展示了完整的线粒体基因组，以及它们的野生亲属样本。序列比较成功地确定了每个单倍群之间的关系，并深入了解了与野生绵羊的关系。五个单倍群的特征是独立分枝，根据蛋白质编码序列，这个辐射在 92 万至 190 万年前共享一个共同的祖先。还使用贝叶斯、最大似然和分区 Bremmer 支持分析来检查各种 mtDNA 成分在告知绵羊之间真实关系方面的效用。结果发现，控制区是 mtDNA 成分，它为使用完整数据集生成的树提供了最高的支持。本研究提供了一个 mtDNA 线粒体基因组面板的核心，可用于评估其他线粒体基因组，并作为评估 mtDNA 小片段的参考集。
