초록 close

Despite that the exotic invasion and rapid range ex-pansion of Asian freshwater Corbicula into new envi-ronments have been of intensive research topic in freshwater ecology, the genetic structures of freshwa-ter Corbicula in its native range remain poorly under-stood. In this study, the genetic structures of two Ko-rean freshwater Corbicula clonal lineages were charac-terized by cross-referencing the nuclear genomic structures with mtDNA sequence analysis. In spite of substantial genetic differences (Nei’s D = 0.363-0.372) and a pronounced level of fixed allelic distinctions (in six of 20 allozyme loci) between Corbicula lineages, no lineage-specific mtDNA differentiation was observed. The evident disjunction between mtDNA sequences and nuclear genomes is a compelling evidence for the existence of interspecific nuclear hybrid genome struc-tures, comprising different combinations of paternal and maternal contributions. This unusual novel find-ing is the first case demonstrating that morphologi-cally and allozymatically distinct, yet mitochondrially identical clonal lineages exist in the genus Corbicula. However, we could not find the ancestral species for these two clonal lineages in the present study, and the answer for this question must wait until the genetic structure of Asian Corbicula taxa is fully characterized.