title: A new karyotype for Rhipidomys (Rodentia, Cricetidae) from Southeastern Brazil.
abstract: In this work we present a new karyotype for Rhipidomys Tschudi, 1845 (Cricetidae, Rodentia) from Brazil. Our chromosome analyses included GTG- and CBG-banding patterns, the localization of the nucleolus organizer regions after silver staining (Ag-NORs) and fluorescence in situ hybridization (FISH) with a telomere probe. The new karyotype is composed of 44 chromosomes and has a fundamental number (number of autosomal arms) of 48. Most Rhipidomys species already karyotyped presented similar complements with 2n=44, but their fundamental numbers varied from FN=46 to 80, a variation that has been mainly attributed to pericentric inversions. The comparison of this new karyotype to those of other Rhipidomys already reported allowed us to conclude that it is a distinctive chromosome complement, which can be of great use as a tool for the very complicated taxonomic identification in this genus.
authors.affiliation: Universidade Federal de Minas Gerais, Laboratório de Citogenética Evolutiva, Departamento de Biologia Geral, Instituto de Ciências Biológicas, Av. Antônio Carlos, 6627 - Pampulha, 31270-910, Belo Horizonte, Brazil.
authors.forename: Ana Heloisa
authors.initials: AH
authors.lastname: de Carvalho
authors.forename: Maria Olímpia Garcia
authors.initials: MO
authors.lastname: Lopes
authors.forename: Marta
authors.initials: M
authors.lastname: Svartman
keywords: FISH; Rhipidomys; chromosome banding