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Chromosome polymorphism in Ctenomys minutus(Rodentia-Octodontidae)

 

 

Tholes Renato O. de Freitas

Departamento de Genética, Universidade Federal do Rio Grande do Sul, Caixa Postal 15053, 91501-970 Porto Alegre, RS, Brasil. E-mail: trof@if1.if.ufrgs.br.

 

 

ABSTRACT

A sample of 101 specimens of Ctenomys minutus was collected along its geographic range. Eight karyotypes (2n = 42, 45, 46a, 46b, 47, 48, 49 and 50) were found. The chromosome polymorphisms were due to Robertsonian rearrangements and tandem fusions. The distribution of polymorphisms indicated three population blocks: northern (2n = 49 and 50), central (2n = 46a, 47, and 48) and southern (2n = 42, 45, and 46b). These findings suggest that this species is undergoing a speciation process due to geographic isolation.

Keywords: Chromosome polymorphism; karyotypes; speciation.

 

 

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