The inheritance of divergent mitochondria in the land snail, Cepaea nemoralis

The mitochondrial genomes of Cepaea nemoralis can differ widely between ind ividuals in the same population. Various hypothesis have been proposed to a ccount for this diversity, including unusually fast evolution and the reten tion of deep lineages in subdivided populations. Another possibility is tha t pulmonate mitochondria are inherited in the doubly uniparental mode, as i n Mytilus, allowing separate maternal and paternal lineages to coexist. In Mytilus, separate lineages may differ by as much as 20% and may pre-date th e origin of the species carrying them. Until now, mitochondrial inheritance has not been studied in any molluscan group except the bivalves. I have investigated it in C, nemoralis through a series of matings, and assayed individuals for evidence of heteroplasmy. I n five matings, mitochondrial inheritance was maternal, and no heteroplasmi c individuals were detected. The maintenance of the divergent haplotypes ca n not be explained by doubly uniparental inheritance.