Sex-limited mitochondrial DNA transmission in the marine mussel Mytilus edulis.
Mitochondrial DNA (mtDNA) was thought to be inherited maternally in animals, although paternal leakage has been reported in mice and Drosophila. Recently, direct evidence of extensive paternal inheritance of mtDNA has been found in the marine mussel Mytilus. We give evidence that whereas female mussels are homoplasmic for a genome that is transmitted to eggs, male mussels are heteroplasmic for this genome and for a second genome that is transmitted preferentially to sperm. The results provide support for the existence of separate male and female routes of mtDNA inheritance in mussels. The two genomes show a base sequence divergence exceeding 20% at three protein coding genes, consistent with long term maintenance of the heteroplasmic state. We propose that the two genomes differ in fitness in males and females, possibly as a result of interaction with nuclear genes.
Molecular Biology Research Group, School of Biological Sciences, University of Wales, Swansea, United Kingdom.
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Skibinski
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Gallagher
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Beynon
D000818:Animals; D001483:Base Sequence; D049872:Bivalvia / Q000235:genetics*; D003001:Cloning, Molecular; D017931:DNA Primers; D004272:DNA, Mitochondrial / Q000235:genetics*; D005111:Extrachromosomal Inheritance; D005260:Female; D008297:Male; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D016133:Polymerase Chain Reaction; D015183:Restriction Mapping
D017931:DNA Primers; D004272:DNA, Mitochondrial