Three Complete Mitochondrial Genomes of Ocellarnaca (Orthoptera, Gryllacrididae) and Their Phylogenies.

Abstract

The Raspy crickets are an interesting group of nocturnal animals that bear femoral-abdominal stridulation and spin silk from the mouthparts. Gryllacridid classification is the subject of ongoing discussion. Here, we present the first mitogenomic sequences for three Ocellarnaca taxa: O. braueri (15,597 bp), O. fuscotessellata (15,607 bp), and O. emeiensis (16,510 bp). Three mitochondrial genomes exhibited the conventional metazoan gene and conserved the characteristic gene order across Gryllacrididae species. Evolutionary selection analyses showed that atp8 was the least evolutionarily constrained mitochondrial gene, whereas cox1 was the most conserved across lineages. The three Ocellarnaca species harbored 5-8 mitochondrial DNA sequence repeats (mtSSRs), falling within the 1-8 range detected in all analyzed Gryllacrididae species. Magnigryllacris and Ocellarnaca exhibited higher mtSSR counts than related genera sharing analogous male abdominal apex morphology. Phylogenomic analyses of 35 mitogenomes from 21 Gryllacrididae species supported Ocellarnaca as monophyletic and a sister to Magnigryllacris (bootstrap = 100%), with O. fuscotessellata resolved as sister to the clade (O. sp. + (O. emeiensis + O. braueri)). This study expands the mitogenomic resources for Ocellarnaca, which will facilitate further resolution of phylogenetic reconstruction within this genus and across Gryllacrididae genera.