IFIBYNE   05513
INSTITUTO DE FISIOLOGIA, BIOLOGIA MOLECULAR Y NEUROCIENCIAS
Unidad Ejecutora - UE
artículos
Título:
The library model for satellite DNA evolution: A case study with the rodents of the genus Ctenomys (Octodontidae) from the Iberá marsh, Argentina.
Autor/es:
CARABALLO D A; BELLUSCIO P M; ROSSI M S
Revista:
GENETICA
Editorial:
SPRINGER
Referencias:
Año: 2010 vol. 138 p. 1201 - 1210
ISSN:
0016-6707
Resumen:
On the basement of the library model of satellite DNAs evolution is the differentialamplification of subfamilies through lineages diversification. However, this idea has rarelybeen explored from an experimental point of view. In the present work, we analyzed copynumber and sequence variability of RPCS, the major satellite DNA present in the genomesof the rodents of the genus Ctenomys, in a closely related group of species and formsinhabiting the Iberá marsh in Argentina. We studied the dependence of these twoparameters at the intrapopulation level because in the case of interbreeding genomes,differences in RPCS copy number are due to recent amplification/contraction events. Wefound an inverse relationship among RPCS copy number and sequence variability:amplifications lead to a decrease of sequence variability, by means of biasedhomogenization of the overall satellite DNA, prevailing few variants. On the contrary, thecontraction events that involve tandems of homogeneous monomers contribute -by defaultminorvariants to become “evident”, which otherwise were undetectable. On the otherhand, all the RPCS sequence variants are totally or partially shared by all the studiedpopulations. As a whole, these results are comprehensible if these RPCS variantspreexisted in the common ancestor of this Ctenomys group.