title: Chromosomal Mapping of Transposable Elements of the Rex Family in the Bristlenose Catfish, Ancistrus (Siluriformes, Loricariidae), from the Amazonian Region.
abstract: Repetitive DNA sequences are present in the genome of basically every known organism, and transposable elements (TE) are one of the most representative sequences involved in chromosomal rearrangements and the genomic evolution of eukaryotes. In fish, the non-LTR retrotransposon TEs, Rex1, Rex3, and Rex6, are widely distributed in fish genomes and are the best-characterized TEs in several species. In the current study, three of these retroelements were physically mapped, through fluorescent in situ hybridization (FISH), in 7 species (71 specimens) of the genus Ancistrus, known as bristlenose catfish: Ancistrus ranunculus, Ancistrus sp. 1 "Purus," Ancistrus sp. 2 "Catalão," Ancistrus dolichopterus, Ancistrus maximus, Ancistrus aff. dolichopterus, and Ancistrus dubius. Rex1, Rex3, and Rex6 showed a cluster distribution, mainly in the terminal and pericentromeric portions, in heterochromatic and euchromatic regions, and did not occur in sexual chromosomes; however, the number and position of the clusters varied between species. This TE distribution suggests its implication in the karyotypic evolution of these species, without affecting the rise of sexual chromosome systems in Ancistrus, in view of their chromosomal variation.
authors.affiliation: Programa de Pós-Graduação em Genética, Conservação e Biologia Evolutiva, Instituto Nacional de Pesquisas da Amazônia,  Petrópolis, Manaus, Amazonas, Brazil.
authors.forename: Ramon Marin
authors.initials: RM
authors.lastname: Favarato
authors.affiliation: Programa de Pós-Graduação em Genética, Conservação e Biologia Evolutiva, Instituto Nacional de Pesquisas da Amazônia,  Petrópolis, Manaus, Amazonas, Brazil.|Centro de Ciências da Saúde, Universidade Federal de Roraima, Boa Vista, Brazil.
authors.forename: Leila Braga
authors.initials: LB
authors.lastname: Ribeiro
authors.affiliation: Programa de Pós-Graduação em Genética, Conservação e Biologia Evolutiva, Instituto Nacional de Pesquisas da Amazônia,  Petrópolis, Manaus, Amazonas, Brazil.
authors.forename: Eliana
authors.initials: E
authors.lastname: Feldberg
authors.affiliation: Departamento de Genética, Instituto de Ciências Biológicas, Universidade Federal do Amazonas, Manaus, Brazil.
authors.forename: Daniele Aparecida
authors.initials: DA
authors.lastname: Matoso
mesh_terms: D000818:Animals; D001938:Brazil; D002397:Catfishes / Q000145:classification / Q000235:genetics*; D002874:Chromosome Mapping; D004251:DNA Transposable Elements; D005260:Female; D017404:In Situ Hybridization, Fluorescence; D059785:Karyotype; D008297:Male; D018626:Retroelements
chemical_list: D004251:DNA Transposable Elements; D018626:Retroelements
keywords: Loricariidae; chromosomal evolution; fish; repetitive DNA; retrotransposons