Molecular Phylogeny of the Wild Populations of Medaka, Oryzias latipes

根据电泳结果将青鳉分为北方群体、南方群体、朝鲜东部群体和中国-朝鲜西部群体4个遗传分化明显的类群，并利用8种6碱基酶的限制性片段长度多态性（RFLP）方法对北方群体和南方群体进行了区分。前者包括10个单倍型，由几个彼此密切相关的类群组成。后者包括89个单倍型，可以分为几个组，具有较低的差异水平。在“北方”单倍型（单倍型1）和“南方”单倍型（单倍型22）之间的序列差异估计为10.1%，这个值被认为是种内单倍型之间的差异非常高。12srRNA、cyt.对B和ND 4进行测序。“北方”和“南方”单倍型之间的序列差异分别为12 srDNA的3.9%（15/586）和cyt的11.6%（64/554）。B型，ND 4区为9.9%（22/223）。虽然不同地区的序列差异值不同，但序列差异值与RFLP分析的估计值（10.1%）接近，表明从分子遗传学角度来看，北方群体和南方群体是高度分化的。

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.