Genic Vadadon and Speciation of Fishes of the Genus Moroco(Cyprinidae)

버들치속(잉어과) 어류의 유전적 변이 및 종분화

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.

한국 및 일본산 버들치속 어류의 유전적 변이, 종의 분류학적 위치 및 계통변화를 구명하기 위하여 전기영동법을 이용, 26개 유전자를 검출 분석하였다. 버들치속 어류의 평균 유전적 변이 정도는 타 어류군에 비하여 낮은 편이었다. 분류상 문제시 되어 오던 한국산 M. lagowskii와 M. oxycephalus 및 일본산 M. steindachneri와 M. jouyi는 각 종 특유의 genetic markers를 갖고 있어 각기 독립된 별종으로 확인되었다. M. lagowskii의 분포지역인 경포호집단은 유전적으로 뚜렷한 차이가 있고 형태적 특징으로 보아 M. percnurus로 추정된다. 각 종의 분화연대를 추정한 결과 이들은 선신세후기에서 홍종세 초기에 걸처 종분화가 되었고, 고 Amur 하 수계를 통하여 이주, 분포한 것으로 추측된다.