Confirmation of the first intronic sequence in the bivalvian mitochondrial genome of (Linnaeus, 1758).

In 2020, the first male-type mitochondrial genome from the clam was published. Apart from the unusual doubly uniparental inheritance of mtDNA, scientists observed a unique (over 4k bp long) extension in the middle of the gene. We have attempted to replicate these data by NGS DNA sequencing and explore further the expression of the long gene. In our study, we report an even longer gene (over 5.5 kbp) with no stop codon separating conserved domains, as well as, based on the rtPCR, a lower relative gene expression pattern of the middle part of the gene (5' = 1; mid = 0.46; 3' = 0.89). Lastly, we sequenced the gene transcript proving the excision of the intronic sequence.