The complete mitochondrial genome of Gammarus roeselii (Crustacea, Amphipoda): insights into mitogenome plasticity and evolution

This study presents the complete mitochondrial (mt) genome sequence, annotation and analysis of the amphipod Gammarus roeselii, a crustacean species widespread in European continental freshwaters. The circular mt genome has a total length of 16,073bp and possesses the 37 canonical mt genes of bilaterians. Particularly noticeable is an unusual case of duplication of the full control region (CR). This duplication was confirmed experimentally in G. roeselii individuals caught in the wild, as it was found in all tested individuals from two distinct populations. Furthermore, comparing multiple mt haplotypes from closely related individuals from the western-most part of the distribution range of G. roeselii allowed us to identify single nucleotide polymorphisms and indels that may constitute valuable markers for phylogeographic analyses of G. roeselii. Finally, we performed a phylogenetic analysis that helped understanding the evolutionary dynamics of the CR.