Genomic context influence on gene evolution

Patterns and rates of nucleotide substitutions, insertions and deletions vary largely across the human genome. GC content heterogeneity explains a substantial fraction of this variability, supporting the use of GC content as a descriptor of different genomic contexts. We recently found evidence for the influence of the genomic context on the evolution and subfunctionalization of the two ASF1 paralogs in vertebrates (Abascal et al, 2013). Whereas 3rd codon positions almost fully diverged in GC-content, most non-synonymous sites remained conserved in the two paralogs. Our results suggested a large impact of the genomic context on divergence at the functional level, including gene expression regulation, amino acid usage, and ultimately, interaction with other partners. Here, we present results of a genome-wide assessment of the influence of the genomic context on the evolution of genes (Aguilar et al, in preparation). We looked for GC-content shifts along phylogenetic trees of vertebrate orthologs and paralogs. When the GC-content varies between orthologs, divergence is expected to be mostly related to the genomic context. In contrast, divergence between paralogs may als