Characterisation of the complete mitochondrial genomes and phylogenetic analysis of ten Oedipodinae grasshoppers (Orthoptera: Acrididae) from Algeria

Abstract

ABSTRACT This study presents the mitogenomes of ten species of Oedipodinae grasshoppers belonging to seven different genera in Algeria; nine of these species were sequenced for the first time, providing the first mitochondrial genomic sequences for their respective genera. Mitogenomes obtained using next-generation sequencing and de-novo assembly techniques range in length from 15,603 to 15,766 bp. These ten mitogenomes are composed of double-stranded cyclic molecules and encode the typical set of 37 genes. The AT content, AT skew and GC skew, codon usage and nucleotide bias of AT are similar across the ten species. All 13 protein-coding genes start with a typical ATN (G/C/T/A) codon, except COX1 in Sphingonotus octofasciatus, which starts with CCG. Two ribosomal RNA genes are located on the N-strand and 22 tRNA genes are folded into typical clover-leaf structures, except for trnS (AGN), which lacks the DHU arm. tRNAs encoded by the N-strand carry two to three times more non-canonical base pairs than tRNAs encoded by the J-strand. The A+T-rich regions of the ten species are variable in terms of nucleotide composition, length and number of repeated units. Moreover, conserved blocks in these regions are identified in all ten species. Additionally, phylogenetic relationships were reconstructed using both ML and BI methods based on all 37 genes. The datasets included the newly sequenced mitogenomes along with previously published data. The results reveal that subfamilies Oedipodinae, Acridinae, Gomphocerinae and Catantopinae are paraphyletic with strong nodal support. As in previous studies, especially the subfamilies Acridinae, Gomphocerinae and Oedipodinae show inconsistencies between taxonomy and phylogeny suggesting the need for a future large-scale revision.