Differentiated ZZ/ZW sex chromosomes in Apareiodon ibitiensis (Teleostei, Parodontidae): cytotaxonomy and biogeography

Autor(es)

Bellafronte, E. ^[1] ; Vicari, M. R. ^[2] ; Artoni, R. F. ^[2] ; Margarido, V. P. ^[3] ; Moreira-Filho, O. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Carlos, Dept Genet & Evolucao, BR-13565905 Sao Carlos, SP - Brazil

^[2] Univ Estadual Ponta Grossa, Dept Biol Estrutural Mol & Genet, BR-84030900 Ponta Grossa, PR - Brazil

^[3] Univ Estadual Oeste Parana, Ctr Ciencias Biol & Saude, BR-85814110 Cascavel, PR - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of Fish Biology; v. 75, n. 9, p. 2313-2325, DEC 2009.
• Citações Web of Science: 17

Resumo

Conventional and molecular chromosomal analyses were carried out on three populations of Apareiodon ibitiensis sampled from the hydrographic basins of the Sao Francisco River and Upper Parana River (Brazil). The results reveal a conserved diploid number (2n = 54 chromosomes), a karyotype formula consisting of 50 m-sm + 4st and a ZZ/ZW sex chromosome system that has not been previously identified for the species. C-banding analysis with propidium iodide staining revealed centromeric and terminal bands located in the chromosomes of the specimens from the three populations and allowed the identification of heteromorphism of heterochromatin regions in the Z and W chromosomes. The number of 18S sites located through fluorescent in situ hybridization (FISH) varied between the populations of the Sao Francisco and Upper Parana Rivers. The location of 5S rDNA sites proved comparable in one pair of metacentric chromosomes. Thus, the present study proposes a ZZ/ZW sex chromosome system for A. ibitiensis among the Parodontidae, and a hypothesis is presented regarding possible W chromosome differentiation stages in this species through DNA accumulation, showing geographical variations for this characteristic, possibly as a consequence of geographical reproductive isolation. (C) 2009 The Authors Journal compilation (C) 2009 The Fisheries Society of the British Isles (AU)

• Processo FAPESP: 08/54620-1 - Citogenética e genética de peixes em regiões impactadas, com ênfase em cabeceiras de rios: o modelo Alto São Francisco, MG
• Beneficiário: Orlando Moreira Filho
• Modalidade de apoio: Auxílio à Pesquisa - Regular