Maria Logacheva has co-authored a paper “The Mitochondrial Genome of a Freshwater Pelagic Amphipod Macrohectopus branickii Is among the Longest in Metazoa” that has been recently published in Genes journal. The researchers sequenced and assembled the mt genome of a pelagic Baikalian amphipod species Macrohectopus branickii. The mt genome is revealed to have an extraordinary length (42,256 base pairs), deviating significantly from the genomes of other amphipod species and the majority of animals. Moreover, mitochondrial genome of M. branickii has a unique gene order within amphipods, duplications of the four tRNA genes and Cox2, and a long non-coding region that makes up about two thirds of the genome’s size. The authors of the paper believe that extension of the mitochondrial genome was most likely caused by multiple duplications and inversions of regions harboring ribosomal RNA genes. Using analysis of the patterns of mitochondrial genome length changes in amphipods and other animal phyla, the scientists demonstrated that the variability in the mt genome length may be a characteristic of certain phyla and is primarily conferred by expansions of non-coding regions. Full text of the paper is available here.