Validation of the male-specific ORF of the paternally-transmitted mtDNA in Mytilus edulis as a protein-coding gene

There appears to be an additional set of sex-specific mtDNA-encoded proteins in bivalve species with doubly uniparental mitochondrial inheritance that may be involved in the transmission of the female and male mito-genomes. In the marine mussel Mytilus edulis, the translation of the female-specific open reading frame (F-ORF) was demonstrated but the translation of the male-specific ORF (M-ORF) remains to be shown. Here we validate the male-specific ORF of the paternal mitogenome in M. edulis as a protein-coding gene. The M-ORF protein was detected only in male gonads and localized in sperm mitochondria and acrosome, suggesting that it is involved in a key sperm function in Mytilus edulis.

Automated summary

There is an additional set of sex-specific mtDNA-encoded proteins in bivalve species with doubly uniparental mitochondrial inheritance that may be involved in the transmission of the female and male mito-genomes. In Mytilus edulis, the translation of the female-specific open reading frame (F-ORF) has been demonstrated, but the translation of the male-specific ORF (M-ORF) is still to be shown. This study validates the M-ORF of the paternal mitogenome in M. edulis as a protein-coding gene. The M-ORF protein is only detected in male gonads and is localized in sperm mitochondria and acrosome, suggesting its involvement in a key sperm function in Mytilus edulis.