Insertion Hot Spots of DIRS1 Retrotransposon and Chromosomal Diversifications among the Antarctic Teleosts Nototheniidae

• Published in: International Journal of Molecular Sciences
• Main Authors: Juliette Auvinet, Paula Graça, Laura Ghigliotti, Eva Pisano, Agnès Dettaï, Catherine Ozouf-Costaz, Dominique Higuet
• Format: Text
• Language: English
• Published: Multidisciplinary Digital Publishing Institute 2019
• Subjects: Nototheniidae; chromosomal rearrangements; species radiation; retrotransposons; FISH; DIRS1; insertion hot spots; Antarctic; The Antarctic; Antarc*
• Online Access: https://doi.org/10.3390/ijms20030701

By their faculty to transpose, transposable elements are known to play a key role in eukaryote genomes, impacting both their structuration and remodeling. Their integration in targeted sites may lead to recombination mechanisms involved in chromosomal rearrangements. The Antarctic fish family Nototheniidae went through several waves of species radiations. It is a suitable model to study transposable element (TE)-mediated mechanisms associated to genome and chromosomal diversifications. After the characterization of Gypsy (GyNoto), Copia (CoNoto), and DIRS1 (YNoto) retrotransposons in the genomes of Nototheniidae (diversity, distribution, conservation), we focused on their chromosome location with an emphasis on the three identified nototheniid radiations (the Trematomus, the plunderfishes, and the icefishes). The strong intrafamily TE conservation and wide distribution across species of the whole family suggest an ancestral acquisition with potential secondary losses in some lineages. GyNoto and CoNoto (including Hydra and GalEa clades) mostly produced interspersed signals along chromosomal arms. On the contrary, insertion hot spots accumulating in localized regions (mainly next to centromeric and pericentromeric regions) highlighted the potential role of YNoto in chromosomal diversifications as facilitator of the fusions which occurred in many nototheniid lineages, but not of the fissions.