title: Microsporidian genomes harbor a diverse array of transposable elements that demonstrate an ancestry of horizontal exchange with metazoans.
abstract: Microsporidian genomes are the leading models to understand the streamlining in response to a pathogenic lifestyle; they are gene-poor and often possess small genomes. In this study, we show a feature of microsporidian genomes that contrasts this pattern of genome reduction. Specifically, genome investigations targeted at Anncaliia algerae, a human pathogen with a genome size of 23 Mb, revealed the presence of a hitherto undetected diversity in transposable elements (TEs). A total of 240 TE families per genome were identified, exceeding that found in many free-living fungi, and searches of microsporidian species revealed that these mobile elements represent a significant portion of their coding repertoire. Their phylogenetic analysis revealed that many cases of ancestry involve recent and bidirectional horizontal transfers with metazoans. The abundance and horizontal transfer origin of microsporidian TEs highlight a novel dimension of genome evolution in these intracellular pathogens, demonstrating that factors beyond reduction are at play in their diversification.
authors.affiliation: Clermont Université, Université d'Auvergne, EA 4678 CIDAM, Clermont-Ferrand, France CNRS, UMR 6023, LMGE, Aubière, France ncorradi@uottawa.ca eric.peyretaillade@udamail.fr emmanuelle.lerat@univ-lyon1.fr.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Parisot
authors.affiliation: Canadian Institute for Advanced Research, Department of Biology, University of Ottawa, Ontario, Canada ncorradi@uottawa.ca eric.peyretaillade@udamail.fr emmanuelle.lerat@univ-lyon1.fr.
authors.forename: Adrian
authors.initials: A
authors.lastname: Pelin
authors.affiliation: Clermont Université, Université d'Auvergne, EA 4678 CIDAM, Clermont-Ferrand, France.
authors.forename: Cyrielle
authors.initials: C
authors.lastname: Gasc
authors.affiliation: CNRS, UMR 6023, LMGE, Aubière, France Clermont Université, Université d'Auvergne, Laboratoire "Microorganismes: Génome et Environnement," Clermont-Ferrand, France.
authors.forename: Valérie
authors.initials: V
authors.lastname: Polonais
authors.affiliation: CNRS, UMR 6023, LMGE, Aubière, France Clermont Université, Université d'Auvergne, Laboratoire "Microorganismes: Génome et Environnement," Clermont-Ferrand, France.
authors.forename: Abdel
authors.initials: A
authors.lastname: Belkorchia
authors.affiliation: CNRS, UMR 6023, LMGE, Aubière, France Clermont Université, Université d'Auvergne, Laboratoire "Microorganismes: Génome et Environnement," Clermont-Ferrand, France.
authors.forename: Johan
authors.initials: J
authors.lastname: Panek
authors.affiliation: CNRS, UMR 6023, LMGE, Aubière, France Clermont Université, Université d'Auvergne, Laboratoire "Microorganismes: Génome et Environnement," Clermont-Ferrand, France.
authors.forename: Hicham
authors.initials: H
authors.lastname: El Alaoui
authors.affiliation: CNRS, UMR 6023, LMGE, Aubière, France Clermont Université, Université d'Auvergne, Laboratoire "Microorganismes: Génome et Environnement," Clermont-Ferrand, France.
authors.forename: David G
authors.initials: DG
authors.lastname: Biron
authors.affiliation: Clermont Université, Université d'Auvergne, Clermont-Ferrand, France, Inserm; U 1103, Clermont-Ferrand, France, CNRS; UMR 6293, Clermont-Ferrand, France.
authors.forename: Emilie
authors.initials: E
authors.lastname: Brasset
authors.affiliation: Clermont Université, Université d'Auvergne, Clermont-Ferrand, France, Inserm; U 1103, Clermont-Ferrand, France, CNRS; UMR 6293, Clermont-Ferrand, France.
authors.forename: Chantal
authors.initials: C
authors.lastname: Vaury
authors.affiliation: Clermont Université, Université d'Auvergne, EA 4678 CIDAM, Clermont-Ferrand, France.
authors.forename: Pierre
authors.initials: P
authors.lastname: Peyret
authors.affiliation: Canadian Institute for Advanced Research, Department of Biology, University of Ottawa, Ontario, Canada ncorradi@uottawa.ca eric.peyretaillade@udamail.fr emmanuelle.lerat@univ-lyon1.fr.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Corradi
authors.affiliation: Clermont Université, Université d'Auvergne, EA 4678 CIDAM, Clermont-Ferrand, France ncorradi@uottawa.ca eric.peyretaillade@udamail.fr emmanuelle.lerat@univ-lyon1.fr.
authors.forename: Éric
authors.initials: É
authors.lastname: Peyretaillade
authors.affiliation: Université de Lyon; Université Lyon 1; CNRS, UMR 5558, Laboratoire de Biométrie et Biologie Évolutive, F-69622 Villeurbanne, France ncorradi@uottawa.ca eric.peyretaillade@udamail.fr emmanuelle.lerat@univ-lyon1.fr.
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Lerat
mesh_terms: D004251:DNA Transposable Elements; D019143:Evolution, Molecular; D022761:Gene Transfer, Horizontal; D016681:Genome, Fungal; D006801:Humans; D016814:Microsporidia / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D008969:Molecular Sequence Data; D009181:Mycoses / Q000382:microbiology*; D010802:Phylogeny
chemical_list: D004251:DNA Transposable Elements
keywords: diversity; genome evolution; horizontal transfers; microsporidia; transposable elements