Mitochondrial genome characterization and phylogenetic relationships of the subfamily Dipsadinae (Reptilia: Colubridae)

The double-banded false coral snake (Erythrolamprus bizona) and the false coral snake (E. pseudocorallus) belong to the subfamily Dipsadinae, a highly diverse group of snakes (~ 800 recognized species) with representatives in the Neotropics (Americas) and Asia (Thermophis sp.) whose phylogenetic relationships and molecular evolution remain incompletely understood. Herein, we sequenced and characterized the complete mitochondrial genomes of these two false coral snakes and assembled de-novo 26 more mitochondrial genomes from dipsadid species from the sequence read archive (transcroptome) data to understand the molecular evolution and the phylogenetic relationships of this group. We complemented our analysis with 12 publicly available mitochondrial genomes yielding a comprehensive dataset of 40 mitochondrial genomes across the Dipsadinae subfamily. Each de-novo mitochondrial genome underwent rigorous annotation and verification prior to comparative analyses, including assessments of nucleotide composition, codon usage bias, selective pressure, and phylogenetic relationships. Mitochondrial genomes of dipsadid snake exhibited a conserved gene order; however, false corals (genus Erythrolamprus) showed distinct patterns of nucleotide composition and codon bias relative to other genera. Selective pressure analyses indicated that all mitochondrial genes across the subfamily are subject to measurable evolutionary constraints. Phylogenetic reconstruction consistently supported the monophyly of Erythrolamprus within the Xenodontini clade. By providing the first integrated comparative mitogenomic assessment focused on this genus, our study expands the mitochondrial genomic resources available for dipsadid snakes and offers new insights into evolutionary diversification, phylogenetic structure, and adaptive patterns within the family. These findings underscore the evolutionary significance of Erythrolamprus, a genus notable for its exceptional diversity and widespread distribution in Central and South America and provide a framework for future research on snake systematics and molecular evolution.