• The Korean Journal of Zoology
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• v.31 no.3
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• pp.236-242
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• 1988

Mitochondrial DNAs of two Mdh allelotypes of the dark chub, Z. temmincki inhabiting in Korean fresh water, were analysed. Samples of each type were collected from four populations, and the fragment patterns for mtdNA of each type were explained from 7 of the eleven restriction enzymes with hexanucleotide recognition site. Genome size was approximately 16.7 kilobases. The highly typical mtdNA fragments of each type were discovered in digestion profiles produced by Eco RI and Pst I enzyrnes. The comparisons of restriction fragment patterns and relative digestion maps permitted the estimation of fragment homology (F) and nucleotide sequence divergence(p). Between the two identical types, sequence divergence(p) was 0.128(MS), and 0.045(MM), ; between the two different types, 0.195 (range 0.177-0.226). These result may provide a distinct difference more than the value derived from allozyrne analysis, and a powerful new molecular approach for assessing genetic-evolutionary relationship among fishes.

• The Korean Journal of Zoology
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• v.32 no.2
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• pp.75-83
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• 1989

Surveys of electrophoretic variation in isozymes and general proteins encoded by 26 loci were conducted to assess species recognition and to estimate the degree of genic variation and species divergence for seven species of the genus Moroco inhabiting in Korea and Japan. Estimates of the average calculated heterozygosity per species of M semotilus, M sp., M percnurus, M lagowskii, M oxycephalus, M steindachneri and M jouyf are low: 0.021, 0.019, 0.051, 0.031, 0.023, 0.046, and 0.007, respectively, and observed heterozygosities are 0.038, 0.022, 0.060, 0.027, 0.025, 0.042, and 0.002, respectively. Allozyme analyses show these species to be distinct genetically with the lafter four species being more closely related one another than any one of them is to the rest of the species. However, these four species (M. lagowskii, M. oxycephalus, M. steindachneri and M jouyi), had unique genetic markers in each species to be recognized as valid species. These results contrast to the previous report of Chung et of. (1986) mainly due to their error in analyzing the isozyme pallems, particularly in MDH and PGI analyses. The genetic distances among M semotilus, M sp., and M percnurus are near the high end of the scale of such estimate for freshwater fish congeners. Based on estimated divergent time of these species of the genus Moroco (5 to 0.6 million years) it is assumed that they are speciated during late Pliocene to middle Pleistocene epoch prior to migration to Korean and Japanese waters through Paleo Amur River system.