SciELO - Scientific Electronic Library Online

vol.26 issue3A rare case of Acute Lymphocytic Leukemia (ALL) presenting with double Philadelphia chromosome: relapse or secondary leukemia?QTL affecting body weight in a candidate region of cattle chromosome 5 author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Services on Demand




Related links


Genetics and Molecular Biology

Print version ISSN 1415-4757


FAGUNDES, Valéria et al. Multiple interstitial ribosomal sites (NORs) in the Brazilian squirrel Sciurus aestuans ingrami (Rodentia, Sciuridae) with 2n = 40: an overview of Sciurus cytogenetics. Genet. Mol. Biol. [online]. 2003, vol.26, n.3, pp.253-257. ISSN 1415-4757.

This is the first time the karyotype of the Brazilian squirrel Sciurusaestuans ingrami, with 2n = 40, is described. The karyotype of this species comprises 18 pairs of biarmed and one minute pair of acrocentric autosomes, a medium-sized submetacentric X and a medium-sized acrocentric Y. Four pairs have an interstitial secondary constriction, co-located with nucleolar organizer regions (NORs), identified by silver-staining technique and fluorescent in situ hybridization (FISH) with ribosomal 18S/28S probes. The occurrence of multiple interstitial NORs is rare in rodents, and this is one of the few examples, identified by a molecular cytogenetics approach.

Keywords : Squirrels; chromosomes; karyotype; NORs; Rodentia.

        · text in English     · English ( pdf )


Creative Commons License All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License