한국 주변에 서식하는 살오징어(Todarodes pacificus)의 계군분석

Abstract

본 연구는 2011년 9월에서 12월까지 동해, 서해, 동중국해의 해구에서 각각 채집된 살오징어들을 형태 및 유전학적 방법으로 계군을 분석하였다. 형태학적 분석은 외투장을 측정하여 외투장 조성 모드를 구성한 후, 평균성숙외투장 20-22cm을 비교하여 성숙을 확인한 후 채집시기에 따라 발생 시기를 추정한 후 각 계군을 추정하였다. 유전학적 분석을 위해 mtDNA COI영역의 유전자를 증폭시켜 약 600bp의 원하는 염기서열을 얻은 후 49개의 유전자형(haplotype)을 결정하였다. 또한 집단간 유전적 차이를 구하기 위해서 Fst값을 구하였고, 집단의 형성 및 분화시기를 알아보기 위해 유전자형 네트워크(haplotype network)를 작성하고, 집단별 유전적 다양성을 알아보았다. 그리고 집단별 유전적 다양성을 알아보기 위해서 유전자형 다양도(haplotype diversity)와 염기다양도(nucleotide diversity)를 구하였다. 1. 형태학적 계군분석을 통하여 동해 북부는 하계군으로 추정되고, 동해 중부, 동해 남부, 동중국해 북부, 서해 북부는 추계군으로 추정된다. 2. 동해 북부는 하계군, 나머지 집단은 추계군으로 추정되지만 집단간 유전적 차이점을 나타내는 Fst 값이 낮게 나타났다. 따라서 형태학적 계군분석으로 구분한 계군과 유전학적 계군분석을 통해 구분한 계군은 서로 다르다. 3. 형태학적으로는 추계군이지만 Fst 값이 동해 중부와 동해 남부, 동해 중부와 서해 북부에서 각각 비교적 큰 차이가 나타남으로 유전적으로 분리된 집단이 존재한다고 판단된다, 특히 동해 중부와 동해 남부는 동일한 해역에서 유전적으로 분리된 집단이 나타났다. 4. 유전자형 네트워크(haplotype network)는 star-like형태이며, 각 집단의 유전자형 다양성(haplotype diversity, h)은 높게 나타났다. 따라서 염기서열 다양성(nucleotide diversity, π)은 낮은 값이 나타남으로 한국 주변에 서식하는 살오징어는 최근에 분화된 것으로 파악된다.

Stock analysis of Todarodes pacificus collected in the East Sea, Yellow Sea and East China Sea during the period from September to December in 2011 was analyzed by morphology and genetic methods. Frequency distributions of mantle length was analyzed by morphological method with measuring size of Todarodes pacificus. Then cohort was estimated to confirm their maturation for mean mantle length comparing with mean mature mantle length 20-22cm. For genetic analysis, after getting desired nucleotide of 600bp by amplifying genes in mtDNA COI region, then decided 49 haplotypes. Also, Fst was figured out to get the genetic differences in each group. To estimate formation of population and differentiation time, the genetic haplotype network was described and then genetic diversity of each group was found out. To get the genetic varieties, haplotype diversity and nucleotie diversity are figured out. The results are summerized as following 4 items: First, according to morphologic cohort analysis, it is estimated that the northern part of East Sea is categorized as summer cohort and that mid /southern part of East Sea, northern part of East China Sea and northern part of West Sea were categorized as autumn cohort. Second, there were estimated that northern part of East Sea was summer cohort and the rest parts were autumn cohort. However Fst which represent genetic difference among groups were low. Therefore, there exist difference of cohort between morphologic cohort analysis and genetic cohort analysis. Third, although middle part of the East Sea, southern part of the East Sea and northern part of the West Sea were autumn cohort in morphologic analysis, there are relatively remarkable difference of Fst in each other. Therefore, there are estimated that genetically separated groups were existed. Although middle part of the East Sea and southern part of the East Sea were situated at the East Sea, genetically separated groups were appeared. Fourth, it was estimated that Todarodes pacificus has been separated in Korean waters recently because of two factors. The former was haplotype network appeared in star-like shape. The latter was high value of haplotype diversity for each group and low value of nucleotide diversity.