title: Transcriptional activity of transposable elements in coelacanth.
abstract: The morphological stasis of coelacanths has long suggested a slow evolutionary rate. General genomic stasis might also imply a decrease of transposable elements activity. To evaluate the potential activity of transposable elements (TEs) in "living fossil" species, transcriptomic data of Latimeria chalumnae and its Indonesian congener Latimeria menadoensis were compared through the RNA-sequencing mapping procedures in three different organs (liver, testis, and muscle). The analysis of coelacanth transcriptomes highlights a significant percentage of transcribed TEs in both species. Major contributors are LINE retrotransposons, especially from the CR1 family. Furthermore, some particular elements such as a LF-SINE and a LINE2 sequences seem to be more expressed than other elements. The amount of TEs expressed in testis suggests possible transposition burst in incoming generations. Moreover, significant amount of TEs in liver and muscle transcriptomes were also observed. Analyses of elements displaying marked organ-specific expression gave us the opportunity to highlight exaptation cases, that is, the recruitment of TEs as new cellular genes, but also to identify a new Latimeria-specific family of Short Interspersed Nuclear Elements called CoeG-SINEs. Overall, transcriptome results do not seem to be in line with a slow-evolving genome with poor TE activity.
authors.affiliation: Dipartimento di Scienze della Vita e dell'Ambiente, Università Politecnica delle Marche, Ancona, Italy; Institut de Génomique Fonctionnelle de Lyon, ENS Lyon, France.
authors.forename: Mariko
authors.initials: M
authors.lastname: Forconi
authors.forename: Domitille
authors.initials: D
authors.lastname: Chalopin
authors.forename: Marco
authors.initials: M
authors.lastname: Barucca
authors.forename: Maria Assunta
authors.initials: MA
authors.lastname: Biscotti
authors.forename: Gianluca
authors.initials: G
authors.lastname: De Moro
authors.forename: Delphine
authors.initials: D
authors.lastname: Galiana
authors.forename: Marco
authors.initials: M
authors.lastname: Gerdol
authors.forename: Alberto
authors.initials: A
authors.lastname: Pallavicini
authors.forename: Adriana
authors.initials: A
authors.lastname: Canapa
authors.forename: Ettore
authors.initials: E
authors.lastname: Olmo
authors.forename: Jean-Nicolas
authors.initials: JN
authors.lastname: Volff
mesh_terms: D000818:Animals; D001483:Base Sequence; D005075:Biological Evolution; D004251:DNA Transposable Elements / Q000235:genetics*; D019143:Evolution, Molecular; D005399:Fishes / Q000235:genetics*; D016678:Genome; D008099:Liver; D008297:Male; D009132:Muscles; D010802:Phylogeny; D018626:Retroelements / Q000235:genetics; D017423:Sequence Analysis, RNA; D020086:Short Interspersed Nucleotide Elements; D013045:Species Specificity; D013737:Testis; D059467:Transcriptome
chemical_list: D004251:DNA Transposable Elements; D018626:Retroelements