Life after the BDD: from sex chromosomes to early developmental enhancers, and back

I will first present my postdoctoral work on enhancer function and evolution. Using mutagenesis libraries in Drosophila melanogaster embryos, we showed that developmental enhancers seem constrained in generating expression outside of their native patterns, while random sequences are capable of driving expression across a broad range of cell types. This led us to propose that the evolution of existing enhancers is limited in its capacity to generate novel phenotypes, whereas the activity of de novo elements might be a primary source of phenotypic novelty. I will then present ongoing efforts from the Galupa lab to dissect the importance of X-linked dosage compensation in mammals. We are currently using CRISPR-based screens and embryoid models to identify which X-linked genes and which cell types require strict sex-chromosome dosage compensation.