Dr. Claire Patiou (IEB)

Small but mighty ORFs - emergence of new genes and regulatory elements

Understanding the genetic basis for the origin and evolution of novel phenotypes and, ultimately, biological diversity is one of the most fundamental questions in evolutionary biology. Within genomes, millions of Open Reading Frames (ORFs) have the potential to encode phenotype-inducing polypeptides. While “canonical” ORFs located within well-conserved genes, have extensively been characterized; short, non-canonical ORFs outside genes have long been considered ''non-coding'' by default, and therefore not functional. Recently, the role of non-canonical ORFs both as regulatory elements of microRNAs (miRNAs) and as starting material for the emergence of new genes de novo (i.e. from ancestrally non-coding sequences) has been demonstrated in a variety of species and genomic contexts. In both plant and fly species, I have used Ribosome-Profiling sequencing data to investigate which ORFs are actively being translated, shedding light on the evolutionary dynamics of non-canonical translation, and how it relates to the emergence of novel genetic elements; highlighting the under-estimated functional potential of non-canonical coding regions.