Not Frozen in the Ice: Large and Dynamic Rearrangements in the Mitochondrial Genomes of the Antarctic Fish

TitleNot Frozen in the Ice: Large and Dynamic Rearrangements in the Mitochondrial Genomes of the Antarctic Fish
Publication TypeJournal Article
Year of Publication2021
AuthorsPapetti, C, Babbucci, M, Dettai, A, Basso, A, Lucassen, M, Harms, L, Bonillo, C, Heindler, FMaximilian, Patarnello, T, Negrisolo, E
JournalGenome Biology and Evolution
Volume13
Issue3
Date Published2021 Mar 01
ISSN1759-6653
KeywordsAnimals, Antarctic Regions, Evolution, Molecular, Fishes, Freezing, Gene Order, Gene Rearrangement, Genes, Mitochondrial, Genome, Mitochondrial, Genomics, Ice, Models, Genetic, Phylogeny, Vertebrates
Abstract

The vertebrate mitochondrial genomes generally present a typical gene order. Exceptions are uncommon and important to study the genetic mechanisms of gene order rearrangements and their consequences on phylogenetic output and mitochondrial function. Antarctic notothenioid fish carry some peculiar rearrangements of the mitochondrial gene order. In this first systematic study of 28 species, we analyzed known and undescribed mitochondrial genome rearrangements for a total of eight different gene orders within the notothenioid fish. Our reconstructions suggest that transpositions, duplications, and inversion of multiple genes are the most likely mechanisms of rearrangement in notothenioid mitochondrial genomes. In Trematominae, we documented an extremely rare inversion of a large genomic segment of 5,300 bp that partially affected the gene compositional bias but not the phylogenetic output. The genomic region delimited by nad5 and trnF, close to the area of the Control Region, was identified as the hot spot of variation in Antarctic fish mitochondrial genomes. Analyzing the sequence of several intergenic spacers and mapping the arrangements on a newly generated phylogeny showed that the entire history of the Antarctic notothenioids is characterized by multiple, relatively rapid, events of disruption of the gene order. We hypothesized that a pre-existing genomic flexibility of the ancestor of the Antarctic notothenioids may have generated a precondition for gene order rearrangement, and the pressure of purifying selection could have worked for a rapid restoration of the mitochondrial functionality and compactness after each event of rearrangement.

URLhttps://doi.org/10.1093/gbe/evab017
DOI10.1093/gbe/evab017
Short TitleGenome Biol Evol
Alternate JournalGenome Biol Evol
PubMed ID33570582
PubMed Central IDPMC7936035
Catégorie HCERES
ACL - Peer-reviewed articles
Publication coopération et recherche SUD
Non