Sergio I. Tiranti, Fernando J. Dyzenchauz, Esteban R. Hasson, Alicia I. Massarini
Evolutionary and systematic relationships among tuco-tucos of the Ctenomys pundti
complex (Rodentia: Octodontidae): a cytogenetic and morphological approach
We present new cytogenetic, morphometric, and sperm morphology data of
eight populations belonging to the C. pundti complex from Southern Córdoba
and Eastern La Pampa Provinces in Argentina. The diploid numbers ranged
from 2n = 44 to 2n = 50, and C- bands revealed a pattern of centromeric and
pericentromeric heterochromatin. Comparisons of G-banded karyotypes
revealed that the 2n = 44 (Holmberg, Santa Catalina, Sampacho), 2n = 46
(Realicó), 2n = 48 (El Guanaco, Guatraché), 2n = 46-48 (Vicuña Mackenna),
and 2n = 50 (Puente Olmos) karyotypes, are closely related. In addition, these
karyotypes show a high degree of homology (95%) with C. talarum talarum,
despite the fact that five chromosomal rearrangements differentiate both taxa.
Discriminant Function Analysis of morphometric data allows to distinguish
three clusters: i) the C. mendocinus species group, ii) C. t. talarum, and iii) populations
of the C. pundti complex proposed herein. The close phylogenetic
relationship between C. talarum and the C. pundti complex, which undoubtedly
belong to the same evolutionary lineage, is well supported by two different
kinds of evidence: the extensive chromosomal homology and the same
symmetric type of sperm. The morphological and chromosomal differences
show that these two forms have diverged recently.
Mammalia, Walter de Gruyter
Print ISSN: 0025-1461
Volume: 69, 04/2005
Pages: 69 - 80
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