title: Eukaryote DIRS1-like retrotransposons: an overview.
abstract: BACKGROUND
  DIRS1-like elements compose one superfamily of tyrosine recombinase-encoding retrotransposons. They have been previously reported in only a few diverse eukaryote species, describing a patchy distribution, and little is known about their origin and dynamics. Recently, we have shown that these retrotransposons are common among decapods, which calls into question the distribution of DIRS1-like retrotransposons among eukaryotes.
  
  
  RESULTS
  To determine the distribution of DIRS1-like retrotransposons, we developed a new computational tool, ReDoSt, which allows us to identify well-conserved DIRS1-like elements. By screening 274 completely sequenced genomes, we identified more than 4000 DIRS1-like copies distributed among 30 diverse species which can be clustered into roughly 300 families. While the diversity in most species appears restricted to a low copy number, a few bursts of transposition are strongly suggested in certain species, such as Danio rerio and Saccoglossus kowalevskii.
  
  
  CONCLUSIONS
  In this study, we report 14 new species and 8 new higher taxa that were not previously known to harbor DIRS1-like retrotransposons. Now reported in 61 species, these elements appear widely distributed among eukaryotes, even if they remain undetected in streptophytes and mammals. Especially in unikonts, a broad range of taxa from Cnidaria to Sauropsida harbors such elements. Both the distribution and the similarities between the DIRS1-like element phylogeny and conventional phylogenies of the host species suggest that DIRS1-like retrotransposons emerged early during the radiation of eukaryotes.
authors.affiliation: UMR 7138 Systématique Adaptation Evolution, Equipe Génétique et Evolution, Université Pierre et Marie Curie Paris 6, Case 5, Bâtiment A, porte 427, 7 quai St Bernard, 75252 Paris Cedex 05, France. piednoel@closun.snv.jussieu.fr
authors.forename: Mathieu
authors.initials: M
authors.lastname: Piednoël
authors.forename: Isabelle R
authors.initials: IR
authors.lastname: Gonçalves
authors.forename: Dominique
authors.initials: D
authors.lastname: Higuet
authors.forename: Eric
authors.initials: E
authors.lastname: Bonnivard
mesh_terms: D005057:Eukaryotic Cells / Q000378:metabolism*; D016678:Genome; D018626:Retroelements
chemical_list: D018626:Retroelements