title: Chromosome mapping of retrotransposable elementsRex1andRex3inLeporinusSpix, 1829 species (Characiformes: Anostomidae) and its relationships among heterochromatic segments and W sex chromosome.
abstract: The family Anostomidae is an interesting model for studies of repetitive elements, mainly because of the presence of high numbers of heterochromatic segments related to a peculiar system of female heterogamety, which is restricted to a few species ofLeporinusgenus. Thus, cytogenetic mapping of the retrotransposable elementsRex1, Rex3,andRex6was performed in sixLeporinusspecies, to elucidate the genomic organization of this genus. The sequencing of theRex1andRex3elements detected different base pair compositions in these elements among species, whereas theRex6element was not identified in the genomes of these species. FISH analysis usingRex1detected different distribution patterns,L. elongatus, L. macrocephalus,andL. obtusidenshad clusters in the terminal regions, whereas the signals were dispersed throughout all of the chromosomes with some signals in the terminal position in other species. TheRex3signals were found mainly in the terminal positions in all the chromosomes of all species. The W chromosomes ofL. elongatus,L. macrocephalus, andL. obtusidenscontained the Rex1 andRex3signal in an interstitial position. These results suggest the emergence of different activity levels for these elements during the evolution of the species analyzed. Despite the conserved karyotype macrostructure speciesLeporinusoften discussed, our results show some variation in hybridization patterns, particularly between the species with specific patterns in their sex chromosomes and species without this differentiated system.
authors.affiliation: Instituto de Biociências; Universidade Estadual Paulista (UNESP) "Julio de Mesquita Filho," Rio Claro; Departamento de Biologia; Laboratório de Citogenética; Rio Claro, SP Brazil.
authors.forename: Rafael
authors.initials: R
authors.lastname: Splendore de Borba
authors.affiliation: Instituto Federal de Educação Ciência e Tecnologia do Piaui; Picos, PI Brazil.
authors.forename: Edson
authors.initials: E
authors.lastname: Lourenço da Silva
authors.affiliation: Instituto de Biociências; Universidade Estadual Paulista (UNESP) "Julio de Mesquita Filho," Rio Claro; Departamento de Biologia; Laboratório de Citogenética; Rio Claro, SP Brazil.
authors.forename: Patrícia Pasquali
authors.initials: PP
authors.lastname: Parise-Maltempi
keywords: FISH; mobile DNA; repetitive sequences; sex chromosome; transposable elements