참게(Eriocheir sinensis)와 꽃게(Portunus trituberculatus)의 2종으로부터 genomic DNA를 분리 추출하였다. 선택된 7개의 OPA-05, OPA-13, OPA-16, OPB-06, OPB-15, OPB-17 and OPD-10의 RAPD primer를 이용하여 identical, polymorphic 그리고 specific fragment를 얻어냈다. 본 연구에서 부안산 참게 집단에서는 505개의 fragment가 나타났고, 꽃게 집단에서는 513개의 fragment가 확인되었다. 참게 집단에서는 165개의 identical fragment가 나타났으며, 이는 primer당 평균적으로 23.6개의 fragment로 확인되었다. 또한 꽃게 집단에서는 66개로서 평균해서 primer당 9.4개의 identical fragment가 나타났다. 참게 집단과 꽃게 집단의 polymorphic fragment는 각각 50개와 14개로 나타났고, 참게 집단과 꽃게 집단의 경우 OPB-17에서 identical fragment가 300 bp의 크기에서 확인되었다. 각각을 비교해 보았을 때 유전적 차이는 참게 집단에서보다 꽃게 집단에서 더 높은 수치를 나타내었고, 2종 사이에서 $0.726{pm}0.004$의 수치를 나타내었다. 7개의 primer를 사용하여 얻어진 dendrogram은 cluster 1(FRESHWATER 01), cluster 2(FRESHWATER 02, 03, 04, 05 및 06), cluster 3(FRESHWATER 07, 08, 09, 10 및 11) 및 cluster 4(SWIMMING 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 and 22)와 같이 4개의 유전적 클러스터로 나뉘어졌다. 꽃게 집단에서 18번째 개체(SWIMMING no. 18)와 17번째 개체 (SWIMMING no. 17) 사이가 가장 가까운 유전적 관계(genetic distance 0.096)를 나타내었다. 궁극적으로 볼 때 참게 집단의 2번째(FRESHWATER no. 02)와 참게 집단의 3번째(FRESHWATER no. 03) 개체 사이가 가장 먼 유전적 거리 (genetic distance=0.770)를 나타내었다. 위에서 언급했던 것처럼 RAPD-PCR 방법은 참게 및 꽃게 2종의 종 판별을 하기 위한 진단적 표지 (diagnostic marker)로 이용할 수 있는 잠재력을 가지고 있는 것으로 확인되었다.
Genomic DNA isolated from two species of Korean freshwater crab(Eriocheir sinensis) and swimming crab(Portunus trituberculatus) was amplified several times by PCR reactions. The seven arbitrarily selected primers OPA-05, OPA-13, OPA-16, OPB-06, OPB-15, OPB-17 and OPD-10 were used to generate the identical, polymorphic, and specific fragments. 505 fragments were identified in the freshwater crab species, and 513 in the swimming crab from Buan: 81 specific fragments(16.0%) in the freshwater crab species and 100(19.5%) in the swimming crab. 165 identical fragments, with an average of 23.6 per primer, were observed in the freshwater crab species. 66 fragments, with an average of 9.4 per primer, were identified in the swimming crab species. The numbers of polymorphic fragments in the freshwater crab and swimming crab were 50 and 14, respectively. The oligonucleotides decamer primer OPB-17 generated identical DNA fragments, approximately 300 bp, in both the freshwater crab and swimming crab species. Compared separately, the average genetic difference was higher in the swimming crab than in the freshwater crab species. The average genetic difference was $0.726{pm}0.004$ between the freshwater crab and swimming crab species. The dendrogram obtained by the seven primers indicates four genetic clusters: cluster 1(FRESHWATER 01), cluster 2(FRESHWATER 02, 03, 04, 05 and 06), cluster 3(FRESHWATER 07, 08, 09, 10 and 11), and cluster 4(SWIMMING 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 and 22). The shortest genetic distance displaying significant molecular difference was between individuals SWIMMING no. 18 and SWIMMING no. 17 from swimming crab(0.096). Ultimately, individual no. 02 of the freshwater crab was most distantly related to freshwater crab no. 03(genetic distance = 0.770). As stated above, the potential of RAPD-PCR to identify diagnostic markers for the identification of two crab species has been demonstrated.
