Characterization of Lophiotoma leucotropis Mitochondrial Genome of Family Turridae and Phylogenetic Considerations within the Neogastropoda.

Abstract

Neogastropoda is a group of marine organisms with an extremely wide distribution that is rich in species and economic and ornamental values, the classification of species in this order has been ongoing for a long time, but there is still a great controversy about whether this order is monophyletic. In this study, we obtained the complete mitogenome of Lophiotoma leucotropis by next-generation sequencing and analyzed the basic structural features of the genome, and we found that the number of genes was consistent with that of most of the Neogastropoda snails, containing 37 genes, including 13 protein-coding genes (PCGs), 2 rRNAs, and 22 tRNAs. Analyzing base content, amino acid content, codon usage preference, and tRNA structure, the mitogenomes of eight species of Turridae were selected for analysis of selection pressures, and it was found that the evolution of species in this family was affected by purifying selection. In addition, by analyzing the rearrangement characteristics, it was found that the sequence of L. leucotropis was consistent with the Conoidea consensus order, and four of the eight species involved in the analysis showed rearrangements. Finally, we constructed a phylogenetic tree by combining PCGs of 60 species within Caenogastropoda and found Neogastropoda to be a monophyletic group, validating the results of morphological classification. The results will provide more references for the classification and species evolution of Neogastropoda, as well as phylogenetic analysis.