title: Two mitochondrial lineages in Korean freshwater Corbicula (Corbiculidae: bivalvia).
abstract: The Korean freshwater Corbicula was surveyed genetically by sequencing 614-bp homologous fragment of mitochondrial cytochrome oxidase I subunit. Among a total of 127 individuals collected from 12 Korean freshwater localities we found only two COI haplotypes and these differed by a total of 9 base substitutions. Although the sequence divergence between the two haplotypes is moderate (p = 1.47%), placing the two mitotypic sequences in the context of Asian mtDNA phylogeny reveals that Korean freshwater Corbicula is comprised of two independent freshwater mitochondrial lineages. These results are in serious disagreement with the long-standing conclusions of earlier conchology-based taxonomic work on Korean Corbicula in which a number of species names (a minimum of 10 nominal species) have been used. This indicates that morphological characteristics alone are poor criteria for species-level identification in this group. In addition, our COI dataset shows that there is an extremely low level of genetic variation in Korean freshwater populations, suggesting that these populations have passed through a severe population bottleneck that greatly reduced their genetic variability. Our data also provide new information on the biogeographic distribution of Korean freshwater Corbicula. When haplotypic frequencies were compared, it was evident that the two Korean freshwater mitochondrial lineages have achieved very different distribution ranges: the predominant lineage (FWKR1) is widely distributed in Korean freshwater systems, whereas the minor lineage (FWKR2) is restricted to a relatively narrow range.
authors.affiliation: Department of Parasitology and Medical Research Institute, College of Medicine, Chungbuk National University, Chongju 361-763, Korea. jkpyou@chungbuk.ac.kr
authors.forename: Joong-Ki
authors.initials: JK
authors.lastname: Park
authors.forename: Byung Lae
authors.initials: BL
authors.lastname: Choe
authors.forename: Keeseon S
authors.initials: KS
authors.lastname: Eom
mesh_terms: D000818:Animals; D001483:Base Sequence; D004272:DNA, Mitochondrial / Q000235:genetics*; D003576:Electron Transport Complex IV / Q000235:genetics*; D019143:Evolution, Molecular; D005828:Genetics, Population; D006239:Haplotypes / Q000235:genetics*; D008928:Mitochondria / Q000235:genetics*; D008969:Molecular Sequence Data; D008974:Mollusca / Q000235:genetics*; D009154:Mutation; D013045:Species Specificity
chemical_list: D004272:DNA, Mitochondrial; D003576:Electron Transport Complex IV