The evolution and function of microRNAs in gene and genome duplication events

Functional innovation is rarely achieved via the de novo genesis of genes. Rather, new genes are most frequently generated by duplication, either in whole or from part of existing genes. Gene duplication is therefore a key molecular process that significantly impacts genome evolution. Duplication of single genes usually results in the loss of the duplicate through pseudogenisation. The dynamics of gene retention that arise from whole genome duplication differ as dosage and genic balance are normally maintained. As a consequence co-adapted sets of genes are often preferentially retained following duplication, as gene loss would result in disruption of genic balance. MicroRNAs (miRNAs) are short single stranded RNA molecules that modulate gene function primarily through translational repression. As such they are key mediators of cellular levels of protein and have frequently been characterized as buffers for gene dosage The aim of this project is to examine the role of miRNAs in the process of gene and whole genome duplication and to understand how these events affect retention of miRNAs and their targets. The project will utilize computational and comparative genomics approaches to examine the patterns of miRNA and target evolution and retention. This will then be used to investigate the role of connectivity of miRNAs and their targets in buffering gene and genome duplication. These computational predictions will be tested experimentally using genetic approaches in Drosophila species.