Meeting Abstract
To date, only two ctenophore species’ mitochondrial genomes have been sequenced. We assembled the mitochondrial genomes from three individuals of the ctenophore Beroe forskalii using Oxford Nanopore and Illumina data. The Beroe forskalii mitochondrial genome contains a conserved NAD2-like open reading frame, as well as a conserved ORF with unknown function. We use a Bayesian hypothesis test of codon usage and find that the unknown ORFs closely match the trinucleotide frequency of canonical mitochondrial genes rather than that of noncoding intergenic sequence. In addition, through simulations and measurements of piN/piS we find that the two unknown ORFs are under negative selection, indicating that they are functionally constrained. Lastly, through synteny analysis of these mitochondrial genomes, we find that mitochondrial rearrangements have occurred between every extant sequenced ctenophore lineage.
