The First Complete Mitochondrial Genome of Lachninae Species and Comparative Genomics Provide New Insights into the Evolution of Gene Rearrangement and the Repeat Region

SIMPLE SUMMARY: The Lachninae is a unique aphid lineage with some particular characteristics. The first complete mitochondrial genome from this subfamily is reported here, with Stomaphis sinisalicis as a representative. The gene arrangement of the new mitogenome differs greatly from the normal gene order of other aphids and insects. The existence of a tandem repeat region in the Lachninae mitogenome may suggest it is probably an ancient feature of aphid mitogenomes. Phylogenetic analysis indicates a basal position of Lachninae within Aphididae. ABSTRACT: Complete mitochondrial genomes are valuable resources for different research fields such as genomics, molecular evolution and phylogenetics. The subfamily Lachninae represents one of the most ancient evolutionary lineages of aphids. To date, however, no complete Lachninae mitogenome is available in public databases. Here we report the Stomaphis sinisalicis mitogenome, representing the first complete mitogenome of Lachninae. The S. sinisalicis mitogenome is consist of 13 protein-coding genes (PCGs), two rRNA genes (rRNAs), 22 tRNA genes (tRNAs), a control region and a large tandem repeat region. Strikingly, the mitogenome exhibits a novel, highly rearranged gene order between trnE and nad1 compared with that of other aphids. The presence of repeat region in the basal Lachninae may further indicate it is probably an ancestral feature of aphid mitogenomes. Collectively, this study provides new insights on mitogenome evolution and valuable data for future comparative studies across different insect lineages.