Estudian las repeticiones en tándem en el genoma de los Grandes simios

Título: Assessing the Role of Tandem Repeats in Shaping the Genomic Architecture of Great Apes

Resumen :
Background: Ancestral reconstructions of mammalian genomes have revealed that evolutionary breakpoint regions are clustered in regions that are more prone to break and reorganize. What is still unclear to evolutionary biologists is whether these regions are physically unstable due solely to sequence composition and/or genome organization, or do they represent genomic areas where the selection against breakpoints is minimal.

Methodology and Principal Findings: Here we present a comprehensive study of the distribution of tandem repeats in great apes. We analyzed the distribution of tandem repeats in relation to the localization of evolutionary breakpoint regions in the human, chimpanzee, orangutan and macaque genomes. We observed an accumulation of tandem repeats in the genomic regions implicated in chromosomal reorganizations. In the case of the human genome our analyses revealed that evolutionary breakpoint regions contained more base pairs implicated in tandem repeats compared to synteny blocks, being the AAAT motif the most frequently involved in evolutionary regions. We found that those AAAT repeats located in evolutionary regions were preferentially associated with Alu elements.

Significance: Our observations provide evidence for the role of tandem repeats in shaping mammalian genome architecture. We hypothesize that an accumulation of specific tandem repeats in evolutionary regions can promote genome instability by altering the state of the chromatin conformation or by promoting the insertion of transposable elements.

Autores : Marta Farre, Montserrat Bosch, Francesc Lopez-Giraldez, Montserrat Ponsa, Aurora Ruiz-Herrera.

Direcciones :
1. Univ Autonoma Barcelona, Dept Biol Cel Lular Fisiol & Immunol, Cerdanyola Del Valles, Spain
2. Yale Univ, Dept Ecol & Evolutionary Biol, New Haven, CT USA
3. IRTA, Cabrils, Spain
4. Univ Autonoma Barcelona, IBB, Cerdanyola Del Valles, Spain