Proto-genes and de novo gene birth
Where do genes come from? Traditionally, most models for new gene evolution invoke modifications of ancestral genes. However, all sequenced genomes contain species-specific genes that lack a family of homologues in other species or lineages. These orphan genes participate in physiological processes and are often thought to drive species-specific adaptations. To understand their origins, I study a mysterious evolutionary phenomenon whereby mutations in non-genic sequences give rise to novel, species-specific, protein-coding genes. This phenomenon is called de novo gene birth. It was long thought to be implausible and remains poorly understood. My work exploits the awesome power of yeast genetics and genomics to uncover the cellular mechanisms and evolutionary dynamics of de novo gene birth. I will discuss how my findings are changing our understanding of what genes are, what cells are made of, and what makes each species unique.