INVESTIGADORES
OJEDA Ricardo Alberto
artículos
Título:
Whole-genome duplications in South American desert rodents (Octodontidae)
Autor/es:
GALLARDO, MILTON H. , G. KAUSEL, A. JIMÉNEZ , C. BACQUET, C.GONZÁLEZ, J. FIGUEROA, N. KÖHLER Y R. OJEDA; RICARDO OJEDA
Revista:
BIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY
Editorial:
WILEY-BLACKWELL PUBLISHING, INC
Referencias:
Año: 2004 vol. 82 p. 443 - 451
ISSN:
0024-4066
Resumen:
The discovery of tetraploidy in the red viscacha rat,
Tympanoctomys barrerae
(4
n
=
102) has emphasized the evolutionary
role of genome duplication in mammals. The tetraploid status of this species is corroborated here by
in situ
PCR and Southern blot analysis of a single-copy gene. The species meiotic configuration strongly suggests a hybrid
derivation. To investigate the origin of
T. barrerae
further, the recently described
Pipanacoctomys aureus
was studied.
This 92-chromosome species also has a duplicated genome size, redundant gene copy number and diploid-like
meiotic pairing, consistent with an event of allotetraploidization. Phylogenetic analysis of mitochondrial sequences
indicates sister-group relationships between these two tetraploid rodents. The new karyotypic data and the phylogenetic
relationships suggest the participation of the ancestral lineages of
Octomys mimax
in the genesis of
P. aureus
. The high overall DNA similarity and shared band homology revealed by genomic Southern hybridization
as well as matching chromosome numbers between
O. mimax
and the descendant tetraploid species support the
notion of introgressive hybridization between these taxa.