PRELIMINARY DATA ON RESTRICTION MAPPING AND DETECTION OF LENGTH VARIATION IN JAPANESE FLOUNDER MITOCHONDRIAL-DNA

We have mapped cleavage sites of ten restriction endonucleases in mito chondrial DNA (mtDNA) of Japanese flounder, Paralichthys olivaceus. Hy bridization with cloned or PCR-amplified fragments determined the map position around structural genes of the mtDNA. Mapping experiments det ected a high level of length variation including heteroplasmy near or within the D-loop containing region. These results provide some basic information for studies on genetic variation of the species important in fisheries and aquaculture. Individual flounders used in this study carry discrete types of mtDNA. The results implies mtDNA typing is use ful for monitoring effectiveness or genetic impact of ongoing stocking of the species into the natural habitat.