SciELO - Scientific Electronic Library Online

 
vol.7 issue4Chromosome polymorphism in Ancistrus cuiabae Knaack, 1999 (Siluriformes: Loricariidae: Ancistrini)Population genetic structuring in pacu (Piaractus mesopotamicus) across the Paraná-Paraguay basin: evidence from microsatellites author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Neotropical Ichthyology

Print version ISSN 1679-6225

Abstract

ROSA, Renata da et al. Cytogenetic analysis of Astyanax laticeps (Cope, 1894) (Ostariophysi: Characidae) from the laguna dos Patos system. Neotrop. ichthyol. [online]. 2009, vol.7, n.4, pp. 601-605. ISSN 1679-6225.  http://dx.doi.org/10.1590/S1679-62252009000400007.

The genus Astyanax is prominent among Characiformes, due to the large number of species found and its wide geographic distribution. In this work, Astyanax laticeps specimens from the laguna dos Patos system were cytogenetically analyzed. A diploid number of 2n = 50 chromosomes distributed into 6m+16sm+16st+12a (FN = 88) was found, without differences between males and females. A few small heterochromatin blocks were observed, besides three more conspicuous C-bands, corresponding to NORs, as confirmed by silver nitrate and CMA3 staining, FISH, and DAPI negative staining. These regions were located in a medium-sized subtelocentric and in a large subtelocentric chromosomal pair, probably because of a deletion of this region in one homologous chromosome, or due to a transposition event between them.

Keywords : Astyanax scabripinnis species complex; rDNA; Homologous transposition.

        · abstract in Portuguese     · text in English     · pdf in English