Molecular Phylogeny of the Wild Populations of Medaka, Oryzias latipes

利用线粒体DNA的8种6碱基酶对北方群体和南方群体进行了限制性片段长度多态性分析，将北方群体和南方群体分为北方群体、南方群体、东韩群体和中国-西韩群体四个不同的群体。前者包括10个单倍型，由几个亲缘关系密切的群体组成。后者包括89种单倍型，可分为几类，差异水平较低。北方单倍型(单倍型1)和南方单倍型(单倍型22)之间的序列差异为10.1%，这一值与种内单倍型之间的差异非常大。编码12srRNA、Cyt的三个不同区域。对B和ND4进行了序列测定。“北方”和“南方”单倍型在12srDNA中的序列差异为3.9%(15/586)，在Cyt中为11.6%(/554)。B和ND4区9.9%(22/223)。虽然不同地区的差异较大，但序列差异值与RFLP分析的估计值(10.1%)接近，说明从分子系统学的角度来看，北方群体和南方群体之间存在着高度的分化。

Oryzias latipes includes four genetically distinct groups, the Northern population, the Southern population, the East Korean population and the china-West Korean population on the basis of electrophoretic data.The Northern population and the Southern population were distinguished by RFLP (using eight 6-base enzymes) of mitochondrial DNA. The former included 10 haplotypes that were composed of a few groups closely related to each other. The latter included 89 haplotypes that could be divided into several groups with a lower level of difference. Sequence divergence was estimated to be 10.1% between a "northern" haplotype (haplotype 1) and a "southern" haplotype (haplotype 22).This value was thought to be very high as those between intraspecific haplotypes.We made two libraries of wkole mitochondrial DNA from a "northern" haplotype (1) and a "southern" haplotype (32). Three different regions encoding 12srRNA, cyt. b and ND4 were sequenced. The sequence differences between "northern" and " southern" haplotypes were 3.9% (15/586) in 12srDNA, 11.6% (64/554) in cyt. b and 9.9% (22/223) in ND4 region. Although the values differed among different regions, sequence divergence values were close to the estimate (10.1%) from RFLP analyses.These results indicated that the Northern population and the Southern population are highly differentiated from a view point of molecular phylogeny.