Mots-Clés

microRNA phylogenomics gene regulation transcription factor RNA-binding protein

Description

microRNAs (``miRNA'') are small regulatory RNAs, which repress specific target mRNAs. Targets are recognized by sequence complementarity between the miRNA and the target mRNA. It has always been considered that phylogenetically complementary sites are functional in mediating miRNA-guided regulation. Here we will explore situations where a miRNA has been lost or gained in a given animal clade, and evaluate which sites are only conserved in the presence of the miRNA. The abundance of sequenced animal genomes will allow a precise measurement of selective presure for thousands of sites and dozens of miRNAs, and it can be anticipated that our understanting of miRNA-guided regulation of the genome will be profoundly transformed. Similar concepts apply to other regulators besides miRNAs (transcription factors and RNA-binding proteins) and we will also explore how far our conclusions can be generalized.