Detecting the action of weak selection in Drosophila

Detecting the action of weak selection in Drosophila

Different data sets from Drosophila indicate that codon usage bias is the result of weak selection. The effectiveness of this kind of selection increases with the effective population size and with the rate of recombination. The action of weak selection can be detected by the comparative intraspecific and interspecific analysis of DNA sequences from coding regions. With this aim we are analyzing:
1- The level and pattern of polymorphism of preferred (slightly advantageous) mutations and unpreferred (slightly deleterious) mutations in different genomic regions in two species with marked differences in their effective size: D. subobscura and D. guanche.
2- The synonymous divergence in genes with drastic interspecific differences in their recombination rate. As a first approach, we are cloning and sequencing in D. subobscura genes located in regions with normal recombination in this species but in regions with a strong reduction rate of recombination in D. melanogaster.
 

April 3, 2005
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