Gender-associated mitochondrial DNA heteroplasmy in the venerid clam Tapes philippinarum (Mollusca Bivalvia).

This paper provides evidence of a gender-associated mitochondrial DNA (mtDNA) heteroplasmy in the clam Tapes philippinarum. The pattern of tissue distribution of the two observed mtDNA types (referred to as M and F) parallels that of the doubly uniparental inheritance system of Mytilus. The mitochondrial genetic features of the clam are related to a different rate of evolution of the M- and F-type mtDNAs. Since clams are known to be phylogenetically very distant from mussels, the present findings support the hypothesis that the mechanism producing gender-associated heteroplasmy should be considered an ancestral character in the Bivalvia.