Novel genes are continuously emerging during evolution, but what drives this process? We have published a study in PLOS Genetics in which we find that the fortuitous appearance of certain combinations of elements in the genome can lead to the generation of new genes. The work, Origins of de novo genes in human and chimpanzee, is very similar to the one we published in arXiv some months ago. It includes some improvements resulting from the peer-review process and from having had more time to think about the paper.
In every genome, there are sets of genes, which are unique to that particular species. In this study, we first identified thousands of genes that were specific to human or chimpanzee. Then, we searched the macaque genome and discovered that this species had significantly less element motifs in the corresponding genomic sequences. These motifs are recognized by proteins that activate gene expression, a necessary step in the formation of a new gene.
The formation of genes de novo from previously non-active parts of the genome was, until recently, considered highly improbable. This study has shown that the mutations that occur normally in our genetic material may be sufficient to explain how this happens. Once expressed, the genes can act as a substrate for the evolution of new molecular functions. This study identified several candidate human proteins that bear no resemblance to any other known protein but which contain signatures of purifying selection.
Jorge Ruiz-Orera, Jessica Hernandez-Rodriguez, Cristina Chiva, Eduard Sabidó, Ivanela Kondova, Ronald Bontrop, Tomàs Marqués-Bonet, M.Mar Albà. Origins of De Novo Genes in Human and Chimpanzee. PLOS Genetics, 2015; 11 (12): e1005721.