title: Occurrence of Natural Hybrids Among Sympatric Karyomorphs in Hoplerythrinus unitaeniatus (Characiformes, Erythrinidae).
abstract: In this study, 43 specimens of Hoplerythrinus unitaeniatus from the São Francisco River basin were chromosomally analyzed by conventional Giemsa staining, C-banding, silver nitrate impregnation, and fluorescence in situ hybridization (FISH) with probes of 5S and 18S rDNA. The diploid numbers found were 50 and 52 chromosomes, showing the existence of two well-defined biological entities in sympatry. Specimens with 51 chromosomes, which showed three distinct karyotypic forms, were also found and are characterized as natural hybrids due to the correspondence with the chromosomes of the specimens with 50 and 52 chromosomes. By FISH using 5S and 18S rDNA probes, it was possible to detect specific chromosomal markers for the specimens with 50 and 52 chromosomes, as well as the occurrence of common sites in both. The specimens with 51 chromosomes showed intermediate patterns for these markers, reinforcing the hypothesis that these are actual natural hybrids. A review and new classification for the karyomorphs of H. unitaeniatus have also been proposed.
authors.affiliation: 1 Universidade Tecnológica Federal do Paraná , Santa Helena, Paraná, Brazil .
authors.forename: Juliana de Fatima
authors.initials: Jde F
authors.lastname: Martinez
authors.affiliation: 2 Centro de Ciências Biológicas e da Saúde, Universidade Estadual do Oeste do Paraná , Cascavel, Paraná, Brazil .
authors.forename: Roberto Laridondo
authors.initials: RL
authors.lastname: Lui
authors.affiliation: 3 Departamento de Genética e Evolução, Universidade Federal de São Carlos , São Carlos, São Paulo, Brazil .
authors.forename: Josiane Baccarin
authors.initials: JB
authors.lastname: Traldi
authors.affiliation: 1 Universidade Tecnológica Federal do Paraná , Santa Helena, Paraná, Brazil .
authors.forename: Daniel Rodrigues
authors.initials: DR
authors.lastname: Blanco
authors.affiliation: 3 Departamento de Genética e Evolução, Universidade Federal de São Carlos , São Carlos, São Paulo, Brazil .
authors.forename: Orlando
authors.initials: O
authors.lastname: Moreira-Filho
mesh_terms: D000818:Animals; D001938:Brazil; D060125:Characiformes / Q000235:genetics*; D005260:Female; D006824:Hybridization, Genetic; D017404:In Situ Hybridization, Fluorescence; D059785:Karyotype; D008297:Male; D011110:Polymorphism, Genetic; D012337:RNA, Ribosomal, 18S / Q000235:genetics; D012341:RNA, Ribosomal, 5S / Q000235:genetics; D061350:Sympatry
chemical_list: D012337:RNA, Ribosomal, 18S; D012341:RNA, Ribosomal, 5S