Insights into the Evolution of Aphid Mitogenome Features from New Data and Comparative Analysis

SIMPLE SUMMARY: Complete mitogenomes provide useful information for investigating the molecular evolution and phylogenetic relationships of insects. This paper reports three new aphid mitogenomes, and provides comparative genomic analyses to investigate the evolution of some unique features of aphid mitogenomes. All three mitogenomes contain the unique tandem repeat region and exhibit notably rearranged gene orders. We provide new support for the idea that tandem repeat region is an ancient feature of aphid mitogenomes, and also demonstrate that the discovered striking gene rearrangements in some aphid mitogenomes are independent clade-specific evolutionary events at certain taxonomic levels. This study improves our understanding of aphid mitogenome evolution. ABSTRACT: The complete mitochondrial genomes and their rearrangement patterns can provide useful information for inferring evolutionary history of organisms. Aphids are one of the insect groups with some unique mitogenome features. In this study, to examine whether some features in aphid mitogenomes are independent species-specific evolutionary events or clade-specific events at certain taxonomic levels, we sequenced three new aphid mitogenomes (Hormaphidinae: Ceratovacuna keduensis, Pseudoregma panicola; Lachninae: Nippolachnus piri) and compared them with all known aphid mitogenomes. The three mitogenomes are 16,059–17,033 bp in length, with a set of 37 typical mitochondrial genes, a non-coding control region and a tandem repeat region. The gene orders of them are all highly rearranged. Within the subfamily Hormaphidinae, the presence of repeat region and mitogenome rearrangement in Cerataphidini species but not in the other two tribes indicate that these may be Cerataphidini-specific features. The same gene rearrangement pattern in the two Lachninae species, N. piri (Tuberolachnini) and Stomaphis sinisalicis (Stomaphidini), supports that this feature should be at least derived from the common ancestor of two tribes. Overall, our data and analyses provide new insights into the evolutionary patterns of gene rearrangement and repeat region in aphid mitogenomes, and further corroborate the potential role of gene rearrangement in elucidating the evolutionary history of different insect lineages.