Data/hora: 02/06/2024 03:53:07

Provedor de dados: 	Genetics and Molecular Biology	
País: 	Brazil	
Título: 	Identification and description of distinct B chromosomes in Cyphocharax modestus (Characiformes, Curimatidae)	
Autores: 	Santos,Lessandra Viviane De Rosa; Foresti,Fausto; Martins,Cesar; Oliveira,Claudio; Wasko,Adriane Pinto.	
Data: 	2008-01-01	
Ano: 	2008	
Palavras-chave: 	B chromosomes; C-banding; Curimatidae; Cyphocharax modestus; Supernumerary chromosomes.	
Resumo: 	Cytogenetic analyses were performed in Cyphocharax modestus, collected at Paranapanema River and Tietê River (São Paulo State, Brazil). A karyotype with 2n = 54 chromosomes was observed in the animals from both Brazilian freshwater river systems. One to four B chromosomes were also detected in individuals from the Paranapanema River, which represents the probable first report of more than a single supernumerary element in a species of the Curimatidae group. C-banding revealed centromeric and telomeric heterochromatin blocks in several chromosomes of the normal karyotype complement of C. modestus. Moreover, while some B chromosomes were characterized by the complete absence of C-bands, others were totally heterochromatic. Although there was a prevalence of B chromosomes in males of C. modestus, at least one supernumerary element was found in males and/or females of several other populations of the species, which suggests that the presence of these chromosomes seems to represent a general trait of C. modestus. A possible origin of the described B chromosomes may be related to the occurrence of a chromosome non-disjunction followed by the loss of euchromatic segments, an event that should have occurred in chromosomes that present conspicuous centromeric heterochromatic blocks and even in chromosomes that lack C-bands in this region, resulting in small supernumerary elements.	
Tipo: 	Info:eu-repo/semantics/article	
Idioma: 	Inglês	
Identificador: 	http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572008000200019	
Editor: 	Sociedade Brasileira de Genética	
Relação: 	10.1590/S1415-47572008000200019	
Formato: 	text/html	
Fonte: 	Genetics and Molecular Biology  v.31 n.1 suppl.0 2008	
Fonte: 	info:eu-repo/semantics/openAccess