Origins, evolution, and physiological implications of de novo genes in yeast

De novo gene birth is the process by which new genes emerge in sequences that were previously noncoding. Over the past decade, researchers have taken advantage of the power of yeast as a model and a tool to study the evolutionary mechanisms and physiological implications of de novo gene birth. We summarize the mechanisms that have been proposed to explicate how noncoding sequences can become protein‐coding genes, highlighting the discovery of pervasive translation of the yeast transcriptome and its presumed impact on evolutionary innovation. We summarize current best practices for the identification and characterization of de novo genes. Crucially, we explain that the field is still in its nascency, with the physiological roles of most young yeast de novo genes identified thus far still utterly unknown. We hope this review inspires researchers to investigate the true contribution of de novo gene birth to cellular physiology and phenotypic diversity across yeast strains and species. This paper makes a case for why yeasts are particularly well suited to address fundamental questions about de novo gene emergence. Several yeast genes of recent de novo origin are known to play important cellular roles. Yeasts also express thousands of species‐specific and strain‐specific de novo open reading frames with unknown biology that offer exciting avenues for discovery. Take Aways Several yeast genes of recent de novo origin play important cellular roles. Yeasts express thousands of de novo sequences with unknown biology. Yeasts are well suited to address fundamental questions about de novo gene birth.