Gene Rearrangements in the Mitochondrial Genome of Gonatopsis borealis and Onychoteuthis compacta Reveal Their Phylogenetic Implications for Oegopsida

Abstract

Among cephalopods, Oegopsida is the largest and most diverse squid lineage. In order to further understand the taxonomy and evolution of the Oegopsida species, improve the molecular database of Oegopsida, and clarify the phylogenetic relationship between them, we obtained the mitochondrial genome sequences of Gonatopsis Borealis and Onychoteuthis Compacta. Their genome sizes were 20148bp and 20491bp, respectively. They all contain 13 protein-coding genes, 23 tRNAs and 2 rRNAs. We downloaded the latest Oegopsida genome sequence available on NCBI, and analyzed their 13 PCGs evolution rate. Apart from ND4, the rest of the genes were affected by Positive selection. Using two Loliginidae species as outgroups, the PCGs of 35 species were rearranged. The results showed that the gene rearrangements of the two species we obtained were in line with the characteristics of Oegopsida, and there were also gene rearrangements in species between families. Phylogenetic analysis was performed and it was found that the topology of the resulting tree was consistent with the morphological identi cation classi cation. These results allow for a better understanding of the phylogenetic relationships of the Oegopsida and enrich the data for the Teuthida.