藏鸡线粒体全基因组序列的测定和分析

通过PCR扩增，测序，拼接，获得藏鸡（Tibetan Chicken）线粒体全基因组序列并进行数据分析处理。藏鸡线粒体全基因组序列全长16783bp，共有13个蛋白质编码基因、2个rRNA基因、22个tRNA基因和1个D-loop区。模拟电子酶切结果显示，藏鸡DraI酶的酶切结果和先前报道的原鸡，茶花鸡，尼西鸡和大理漾濞黄鸡的酶切结果都不相同，为藏鸡特有。基于D-loop区全序列和13个蛋白质编码基因序列，采用N-J算法与原鸡属4个种，3个亚种和3个家鸡品系构建系统进化树：初步确定藏鸡起源于红原鸡，与家鸡中的来航鸡、白洛克鸡亲缘关系最近，但是藏鸡的进化与来航鸡、白洛克鸡这两个家鸡品系又显得相对独立。推测可能原因是藏鸡的祖先在进入高原以后处于相对封闭的环境，从而形成了独特群体遗传特性。

Complete Sequence and Gene Organization of Tibetan Chicken Mitochondrial Genome

Using PCR amplification, sequencing and assembling, we obtained the complete mitochondrial genome of Tibetan chicken. The complete mitochondrial genome was 16 783 bp in length. It contained 37 genes (13 protein coding genes, 2 rRNA, 22 tRNA) and a control region. The deduced restriction map revealed a unique pattern of Dra I restriction in Tibetan chicken. Phylogenetic trees based on the D-loop locus and the 13 protein coding genes by Neighbor-joining and Maximum Parsimony analysis indicated that the red junglefowl was the direct ancestor of Tibetan chicken and Tibetan chicken was closest to white leghorn and white plymouth rock, although the evolution of Tibetan chicken appeared to be relatively independent from them. A possible explanation is that the ancestor of Tibetan chicken lived in a relatively isolated environment after entering into the high altitude area and developed unique genetic characters.