Karyotypic variation in the Andean rodent Phyllotis xanthopygus (Waterhouse, 1837) (Rodentia, Cricetidae, Sigmodontinae)

By

Labaroni, Carolina Alicia
Malleret, Matías
Novillo, Agustina
Ojeda, Agustina
Rodriguez, Daniela
Cuello, Pablo
Ojeda, Ricardo A. (Ricardo Alberto)
Marti, Dardo Andrea
Lanzone, Cecilia

Type

Article

Date of Publication

2014

Original Publication

Comparative cytogenetics : international journal of plant & animal cytogenetics, karyosystematics and molecular systematics

Volume

8

Series / Issue

Issue: 4

Pages

369-381

Subjects

Chromosomes , constitutive heterochromatin , fluorochromes , genetic variability , Mammals

Contributed by

Pensoft Publishers

Language

English

Published by

St. Petersburg, Russia [Published] with technical support of Zoological Institute RAS [2007]-

Identifiers

DOI: https://doi.org/10.3897/CompCytogen.v8i4.8115

 

Abstract

Phyllotis xanthopygus (Waterhouse, 1837) is an Andean rodent endemic to South America. Despite its wide geographical distribution in Argentina, few individuals have been studied on the cytogenetic level and only through conventional staining. In this work, chromosome characterization of Argentine samples of this species was performed using solid staining, C-banding and base-specific fluorochromes. Twenty two specimens were analyzed, collected in the provinces of Jujuy, Catamarca, and the north and south of Mendoza. All studied specimens showed 2n=38, having mostly the bi-armed autosomes, metacentric or submetacentric. Fundamental Number varied between 70 and 72. These changes were due to the presence of chromosome heteromorphisms in individuals from southern Mendoza and Jujuy. C-banding revealed pericentromeric blocks of constitutive heterochromatin in most chromosomes. Acrocentric chromosomes involved in heteromorphisms showed high variation in the amount of heterochromatin within and among populations. Additionally, banding with fluorochromes (DAPI and chromomycin A3) revealed homologous localization of AT and GC rich regions among chromosomes of the different populations analyzed. Comparisons among heteromorphic pairs suggested, however, that the variation might be the result of complex chromosome rearrangements, involving possibly amplifications and/or deletions of heterochromatic segments. These results are in accordance with molecular studies that indicate genetic variability within and among the populations of this taxon.