A single mitochondrial lineage is shared by morphologically and allozymatically distinct freshwater Corbicula clones.
Despite that the exotic invasion and rapid range expansion of Asian freshwater Corbicula into new environments have been of intensive research topic in freshwater ecology, the genetic structures of freshwater Corbicula in its native range remain poorly understood. In this study, the genetic structures of two Korean freshwater Corbicula clonal lineages were characterized 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 structures, comprising different combinations of paternal and maternal contributions. This unusual novel finding is the first case demonstrating that morphologically 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.
Park
Joong-Ki
JK
School of Biological Sciences, Seoul National University, Korea.
Lee
Jun-Sang
JS
Kim
Won
W
D000818:Animals; D001483:Base Sequence; D006824:Hybridization, Genetic; D007527:Isoenzymes / Q000235:genetics; D007723:Korea; D008928:Mitochondria / Q000235:genetics*; D008969:Molecular Sequence Data; D008974:Mollusca / Q000145:classification / Q000201:enzymology / Q000235:genetics* / Q000648:ultrastructure*; D010802:Phylogeny; D016415:Sequence Alignment
D007527:Isoenzymes