Matsui Masafumi, Nishikawa Kanto, Misawa Yasuchika, Tanabe Shingo
Graduate School of Human and Environmental Studies, Kyoto University, Kyoto, Japan.
Zoolog Sci. 2007 Jul;24(7):746-51. doi: 10.2108/zsj.24.746.
We conducted an electrophoretic survey to examine systematic relationships of a lotic-breeding salamander Hynobius okiensis endemic to Dogo Island of the Oki Islands, Japan, with several lentic and lotic-breeding Japanese species. Genetically H. okiensis with 2n=56 chromosomes was closer to the lentic-breeding H. nebulosus group (H. nebulosus and H. dunni) with the same chromosome number than to the lotic-breeding H. naevius group (H. naevius and H. kimurae) and H. boulengeri with 58 chromosomes. Chromosome number reduction from 58 to 56, possibly accompanied with a change in breeding environment from streams to still waters, is estimated to have first occurred in the nebulosus group of Hynobius. A reversal only in breeding habits then seems to have followed in steep, montane environments of the small island of Dogo, resulting in the speciation of H. okiensis.
我们进行了一项电泳调查，以研究日本隐岐群岛出石岛特有的溪流繁殖蝾螈——冈氏蝾螈（Hynobius okiensis）与几种日本静水生境和溪流繁殖蝾螈物种之间的系统发育关系。在遗传学上，具有2n = 56条染色体的冈氏蝾螈与具有相同染色体数目的静水生境繁殖的云间蝾螈组（云间蝾螈H. nebulosus和钝口蝾螈H. dunni）的亲缘关系，比与溪流繁殖的疣螈组（疣螈H. naevius和木村氏疣螈H. kimurae）以及具有58条染色体的 Boulenger's salamander（H. boulengeri）更近。染色体数目从58条减少到56条，可能伴随着繁殖环境从溪流到静水的变化，据估计首次发生在隐鳃鲵属的云间蝾螈组。随后，在出石小岛陡峭的山地环境中，似乎仅繁殖习性发生了逆转，导致了冈氏蝾螈的物种形成。
