Genetic relationship between cultured populations of Pacific oyster revealed by RAPD analysis

We developed random amplified polymorphic DNA (RAPD) analysis for the assessment of the genetic relationship between cultured populations of the Pacific oyster Crassostrea gigas Thunberg in Hiroshima and Goseong, the largest oyster farming areas in Japan and Korea, respectively. Of 25 arbitrary primers comprising decamer nucleotides of random sequences, polymerase chain reaction amplifications with 5 different primers gave reproducible electrophoretic patterns. A total of 49 RAPD markers were clearly identified for the Hiroshima and Goseong populations, and 46 markers were polymorphic presenting mean polymorphism rates of the respective populations at 92.29% and 93.32%. Pairwise genetic distances of each 20 individuals from these populations served to produce a UPGMA dendrogram. The dendrogram comprised two main clusters, one of which was a nested cluster including all individuals of the Hiroshima population along with 12 individuals of the Goseong population, and the other cluster included the remaining individuals of the Goseong population. Results indicate that RAPD markers are useful for the assessment of the genetic relationships between populations of the Pacific oyster and further that a significant portion of oysters imported from Korea could be genetically related to the Hiroshima population.