Data/hora: 02/06/2024 05:18:51

Provedor de dados: 	Genetics and Molecular Biology	
País: 	Brazil	
Título: 	X1X1X2X2/X1X2Y sex chromosome systems in the Neotropical Gymnotiformes electric fish of the genus Brachyhypopomus	
Autores: 	Cardoso,Adauto Lima; Pieczarka,Julio Cesar; Nagamachi,Cleusa Yoshiko.	
Data: 	2015-06-01	
Ano: 	2015	
Palavras-chave: 	Sex chromosome fusion; Sexual trivalent; Meiosis.	
Resumo: 	Several types of sex chromosome systems have been recorded among Gymnotiformes, including male and female heterogamety, simple and multiple sex chromosomes, and different mechanisms of origin and evolution. The X1X1X2X2/X1X2Y systems identified in three species of this order are considered homoplasic for the group. In the genus Brachyhypopomus, only B. gauderio presented this type of system. Herein we describe the karyotypes of Brachyhypopomus pinnicaudatus and B. n. sp. FLAV, which have an X1X1X2X2/X1X2Y sex chromosome system that evolved via fusion between an autosome and the Y chromosome. The morphology of the chromosomes and the meiotic pairing suggest that the sex chromosomes of B. gauderio and B. pinnicaudatus have a common origin, whereas in B . n. sp. FLAV the sex chromosome system evolved independently. However, we cannot discard the possibility of common origin followed by distinct processes of differentiation. The identification of two new karyotypes with an X1X1X2X2/X1X2Y sex chromosome system in Gymnotiformes makes it the most common among the karyotyped species of the group. Comparisons of these karyotypes and the evolutionary history of the taxa indicate independent origins for their sex chromosomes systems. The recurrent emergence of the X1X1X2X2/X1X2Y system may represent sex chromosomes turnover events in Gymnotiformes.	
Tipo: 	Info:eu-repo/semantics/article	
Idioma: 	Inglês	
Identificador: 	http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572015000200213	
Editor: 	Sociedade Brasileira de Genética	
Relação: 	10.1590/S1415-4757382220140189	
Formato: 	text/html	
Fonte: 	Genetics and Molecular Biology  v.38 n.2 2015	
Fonte: 	info:eu-repo/semantics/openAccess