title: Gender-Associated Mitochondrial DNA Heteroplasmy in Somatic Tissues of the Endangered Freshwater Mussel Unio crassus (Bivalvia: Unionidae): Implications for Sex Identification and Phylogeographical Studies.
abstract: Some bivalve species possess two independent mitochondrial DNA lineages: maternally (F-type) and paternally (M-type) inherited. This phenomenon is called doubly uniparental inheritance. It is generally agreed that F-type mtDNA is typically present in female somatic and gonadal tissues as well as in male somatic tissues, whereas the M-type mtDNA occurs only in male germ line and gonadal tissue. In the present study, the mtDNA heteroplasmy (for both F and M genomes) in male somatic tissues of Unio crassus (Philipsson, 1788), species threatened with extinction, has been confirmed. Taking advantage from the presence of Mcox1 marker only in male somatic tissues, we developed a new method of sex identification in this endangered species, using nondestructive tissue sampling. Probability of correct sex identification was estimated at 97.5%. The present study is the first report on gender-associated mitochondrial DNA heteroplasmy in male somatic tissues of thick-shelled river mussel and first approach to U. crassus sex identification at molecular level. Our study also confirmed the utility of paternally inherited Mcox1 gene fragment as a complementary molecular tool for resolving phylogeographical relationships among populations of thick-shelled river mussel.
authors.affiliation: Department of Genetics, University of Gdansk, 80-308 Gdansk, Poland.
authors.forename: Monika
authors.initials: M
authors.lastname: Mioduchowska
authors.affiliation: Department of Genetics, University of Gdansk, 80-308 Gdansk, Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Kaczmarczyk
authors.affiliation: Institute of Nature Conservation, Polish Academy of Sciences, 31-120 Krakow, Poland.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Zając
authors.affiliation: Institute of Nature Conservation, Polish Academy of Sciences, 31-120 Krakow, Poland.
authors.forename: Tadeusz
authors.initials: T
authors.lastname: Zając
authors.affiliation: Department of Genetics, University of Gdansk, 80-308 Gdansk, Poland.
authors.forename: Jerzy
authors.initials: J
authors.lastname: Sell
mesh_terms: D000818:Animals; D004272:DNA, Mitochondrial / Q000235:genetics*; D005260:Female; D014644:Genetic Variation; D016678:Genome; D008297:Male; D058974:Phylogeography; D012732:Sex Determination Analysis / Q000379:methods*; D012737:Sex Factors; D049876:Unionidae / Q000235:genetics*
chemical_list: D004272:DNA, Mitochondrial