Data/hora: 03/06/2024 08:52:00

Provedor de dados: 	83	
País: 	Brazil	
Título: 	Comparative cytogenetics in Astyanax (Characiformes: Characidae) with focus on the cytotaxonomy of the group	
Autores: 	Tenório,Renata Cristina Claudino de Oliveira; Vitorino,Carla de Andrade; Souza,Issakar Lima; Oliveira,Claudio; Venere,Paulo Cesar.	
Data: 	2013-09-01	
Ano: 	2013	
Palavras-chave: 	C-banding; CMA3 and DAPI fluorochromes; Fish chromosome; RDNA genes; NORs.	
Resumo: 	Astyanax is a diverse group of Neotropical fishes, whose different forms occupy different environments. This great diversity is also reflected on cytogenetic aspects and molecular markers, which have repeatedly been demonstrated by cytogenetic studies. In order to characterize the karyotype of species of this genus, six species were studied: Astyanax altiparanae, A.argyrimarginatus, A. elachylepis, A. xavante, and two new species provisionally called Astyanax sp. and A. aff. bimaculatus. A detailed cytogenetic study based on conventional staining with Giemsa, AgNORs, C-banding, base-specific fluorochromes, and FISH using ribosomal genes 18S and 5S was conducted, aiming to understand some of the chromosomal mechanisms associated with the high diversification that characterizes this group and culminated with the establishment of these species. The results showed 2n = 50 chromosomes for five species and a karyotype with 52 chromosomes in Astyanax sp. Small variations in the macrostructure of the karyotypes were identified, which were quite relevant when analyzed by classical banding, fluorochromes, and FISH methods. These differences among Astyanax spp. (2n = 50) are largely due to changes in the amount and types of heterochromatic blocks. Astyanax sp (2n = 52), in addition to variations due to heterochromatic blocks, has its origin possibly by events of centric fission in a pair of chromosomes followed by minor rearrangements.These results show an interesting karyotypic diversity in Astyanax and indicate the need of a review of the group referred as A. aff. bimaculatus and the description of Astyanax sp., including the possibility of inclusion of this unit in another genus.	
Tipo: 	Info:eu-repo/semantics/article	
Idioma: 	Inglês	
Identificador: 	http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252013000300553	
Editor: 	Sociedade Brasileira de Ictiologia	
Relação: 	10.1590/S1679-62252013000300008	
Formato: 	text/html	
Fonte: 	Neotropical Ichthyology  v.11 n.3 2013	
Fonte: 	info:eu-repo/semantics/openAccess