title: Genetic uniformity and long-distance clonal dispersal in the invasive androgenetic Corbicula clams.
abstract: The clam genus Corbicula is an interesting model system to study the evolution of reproductive modes as it includes both sexual and asexual (androgenetic) lineages. While the sexual populations are restricted to the native Asian areas, the androgenetic lineages are widely distributed being also found in America and Europe where they form a major aquatic invasive pest. We investigated the genetic diversity of native and invasive Corbicula populations through a worldwide sampling. The use of mitochondrial and nuclear (microsatellite) markers revealed an extremely low diversity in the invasive populations with only four, undiversified, genetic lineages distributed across Europe and America. On the contrary, in the native populations, both sexual and androgenetic lineages exhibited much higher genetic diversity. Remarkably, the most abundant and widely distributed invasive forms, the so-called form A and form R found in America and Europe respectively, are fixed for the same single COI (cytochrome c oxydase subunit I) haplotype and same multilocus genotype. This suggests that form R, observed in Europe since the 1980s, derived directly from form A found in America since the 1920s. In addition, this form shares alleles with some Japanese populations, indicating a Japanese origin for this invasive lineage. Finally, our study suggests that few androgenetic Corbicula individuals successfully invaded the non-native range and then dispersed clonally. This is one striking case of genetic paradox raising the issue of invasive and evolutionary success of genetically undiversified populations.
authors.affiliation: Laboratory of Evolutionary Genetics and Ecology, Research Unit in Environmental and Evolutionary Biology, University of Namur, 5000, Namur, Belgium.
authors.forename: Lise-Marie
authors.initials: LM
authors.lastname: Pigneur
authors.forename: Emilie
authors.initials: E
authors.lastname: Etoundi
authors.forename: David C
authors.initials: DC
authors.lastname: Aldridge
authors.forename: Jonathan
authors.initials: J
authors.lastname: Marescaux
authors.forename: Nina
authors.initials: N
authors.lastname: Yasuda
authors.forename: Karine
authors.initials: K
authors.lastname: Van Doninck
mesh_terms: D000483:Alleles; D000818:Animals; D001499:Bayes Theorem; D002467:Cell Nucleus / Q000235:genetics; D049874:Corbicula / Q000235:genetics*; D004272:DNA, Mitochondrial / Q000235:genetics; D014644:Genetic Variation; D005828:Genetics, Population; D005838:Genotype; D006239:Haplotypes; D058865:Introduced Species; D018895:Microsatellite Repeats; D010802:Phylogeny; D012100:Reproduction, Asexual / Q000235:genetics; D017422:Sequence Analysis, DNA
chemical_list: D004272:DNA, Mitochondrial
keywords: androgenesis; invasive species; phylogenetics; phylogeography; reproductive strategies