Komiyama Tomoyoshi, Ikeo Kazuho, Tateno Yoshio, Gojobori Takashi
Center for Information Biology and DNA Data Bank of Japan, National Institute of Genetics, Research Organization of Information and Systems, Mishima, Shizuoka 411-8540, Japan.
Mol Phylogenet Evol. 2004 Oct;33(1):16-21. doi: 10.1016/j.ympev.2004.04.019.
With the aim of elucidating the evolutionary origin of Japanese domesticated chickens, this study evolutionarily analyzed 85 chicken mtDNA sequences. Thirty-four various ornamental chickens, 42 fighting cocks (Shamo), and nine long-crowing chickens (Naganakidori) were included. Of the Shamo, 18 were sampled from Okinawa, while the remaining 24 were collected in other islands around Japan. In addition, three Southeast Asian Junglefowls were used as a reference to determine the common ancestor of Japanese domesticated chickens. A phylogenetic tree was constructed for the 88 mtDNA sequences revealing that the Shamo group from Okinawa clearly diverged from the other Japanese domesticated chickens studied. This strongly suggests that all Japanese domesticated chickens, including the ornamental varieties and Naganakidori, derived from the ancestors of the Shamo in Okinawa. To create novel varieties of ornamental chickens, intensive artificial selection is imposed on ancestral Shamo populations, resulting in profoundly differentiated Japanese domesticated chickens.
为了阐明日本家养鸡的进化起源，本研究对85个鸡线粒体DNA序列进行了进化分析。其中包括34种不同的观赏鸡、42只斗鸡（日本斗鸡）和9只长尾鸡。在日本斗鸡中，18只从冲绳岛采样，其余24只在日本其他岛屿收集。此外，还使用了三只东南亚原鸡作为参考，以确定日本家养鸡的共同祖先。构建了88个线粒体DNA序列的系统发育树，结果显示来自冲绳岛的日本斗鸡群体与其他所研究的日本家养鸡明显不同。这有力地表明，所有日本家养鸡，包括观赏品种和长尾鸡，都源自冲绳岛日本斗鸡的祖先。为了培育新的观赏鸡品种，对祖先日本斗鸡群体进行了高强度的人工选择，从而产生了差异极大的日本家养鸡。
