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Wednesday, 28th November, 2012, 11:00
"Unequal evolution after gene duplication is mediated by positive selection"
Gene duplication plays a major role in genome evolution and is widely accepted to be an important source of new gene functions. Different scenarios have been proposed to explain the retention of the two copies: gain of an advantageous function by one of the copies (neofunctionalization), split of the ancestral function between the two copies (subfunctionalization) and, increased gene dosage advantage.
The analyses published so far have not conclusively identified any of these models as the dominating one. Taking advantage of the reasonable highquality mouse and rat genomes, we have obtained an exhaustive set of duplicated genes that were originated at different times during rodent evolution and measured the strength of purifying selection and of positive selection at different time periods. Our findings indicate that after gene duplication, the daughter copy typically evolves 3 to 5 times faster than the parental copy, and the impact of positive selection increases about 3.5 fold with respect to the ancestral gene. After the initial acceleration the rate gradually decreases until it reaches the levels observed before the duplication. In addition, only the faster evolving copy displays significant differences in tissueexpression patterns compared to the singlecopy ortholog. Our results provide strong evidence that neofunctionalization is the most common scenario driving the fate of recently duplicated rodent genes.
Speaker: Cinta Pegueroles - Biomedical Informatics - GRIB (IMIM/ UPF)
Room Aula (473.10)
