title: Chromosomal mapping of H3 histone and 5S rRNA genes in eight species of Astyanax (Pisces, Characiformes) with different diploid numbers: syntenic conservation of repetitive genes.
abstract: The genus Astyanax is widely distributed from the southern United States to northern Patagonia, Argentina. While cytogenetic studies have been performed for this genus, little is known about the histone gene families. The aim of this study was to examine the chromosomal relationships among the different species of Astyanax. The chromosomal locations of the 5S rRNA and H3 histone genes were determined in A. abramis, A. asuncionensis, A. altiparanae, A. bockmanni, A. eigenmanniorum, A. mexicanus (all 2n = 50), A. fasciatus (2n = 46), and A. schubarti (2n = 36). All eight species exhibited H3 histone clusters on two chromosome pairs. In six species (A. abramis, A. asuncionensis, A. altiparanae, A. bockmanni, A. eigenmanniorum, and A. fasciatus), syntenic clusters of H3 histone and 5S rDNA were observed on metacentric (m) or submetacentric (sm) chromosomes. In seven species, clusters of 5S rDNA sequences were located on one or two chromosome pairs. In A. mexicanus, 5S rDNA clusters were located on four chromosome pairs. This study demonstrates that H3 histone clusters are conserved on two chromosome pairs in the genus Astyanax, and specific chromosomal features may contribute to the genomic organization of the H3 histone and 5S rRNA genes.
authors.affiliation: Instituto de Biociências, Departamento de Biologia, Laboratório de Citogenética, Universidade Estadual Paulista "Júlio de Mesquita Filho" (UNESP), Av. 24A, 1515, ZIP: 13506-900, Rio Claro, SP, Brazil.|Instituto de Biociências, Departamento de Biologia, Laboratório de Citogenética, Universidade Estadual Paulista "Júlio de Mesquita Filho" (UNESP), Av. 24A, 1515, ZIP: 13506-900, Rio Claro, SP, Brazil.
authors.forename: Diovani
authors.initials: D
authors.lastname: Piscor
authors.affiliation: Instituto de Biociências, Departamento de Biologia, Laboratório de Citogenética, Universidade Estadual Paulista "Júlio de Mesquita Filho" (UNESP), Av. 24A, 1515, ZIP: 13506-900, Rio Claro, SP, Brazil.|Instituto de Biociências, Departamento de Biologia, Laboratório de Citogenética, Universidade Estadual Paulista "Júlio de Mesquita Filho" (UNESP), Av. 24A, 1515, ZIP: 13506-900, Rio Claro, SP, Brazil.
authors.forename: Patricia Pasquali
authors.initials: PP
authors.lastname: Parise-Maltempi
mesh_terms: D000818:Animals; D060125:Characiformes / Q000145:classification / Q000235:genetics*; D002874:Chromosome Mapping; D004171:Diploidy; D020459:Genes, rRNA; D006657:Histones / Q000235:genetics*; D017404:In Situ Hybridization, Fluorescence; D059785:Karyotype; D012341:RNA, Ribosomal, 5S / Q000235:genetics; D026801:Synteny
chemical_list: D006657:Histones; D012341:RNA, Ribosomal, 5S
keywords: ADN répétés; Astyanax schubarti; FISH; Mexican blind cavefish; karyotype evolution; repetitive DNAs; tétra aveugle; évolution caryotypique