Invited Speaker: Zhang Zhaolei

Zhaolei Zhang, Associate Professor, Department of Molecular Genetics, University of Toronto Faculty of Medicine, Toronto, Canada. He received his B.S. in Biophysics from Nankai University and PhD in Biophysics (protein crystallography) from UC Berkeley (with Sung-Hou Kim). He was a post-doctoral fellow with Mark Gerstein at Yale University from 2001 to 2004, and joined University of Toronto in 2004. He was promoted to
tenured Associate Professor in 2009.

MicroRNA (miRNA) mediated gene regulation is of critical functional importance in animals and is often thought to be largely constrained during evolution. Here we show that a number of miRNA binding sites display high level of population differentiation in humans and thus are likely targets of local adaptation. In a subset we demonstrate that allelic differences modulate miRNA regulation in mammalian cells, including an interaction between miR-155 and TYRP1, a melanosomal enzyme associated with human pigmentary differences. We identify alternate alleles of TYRP1 that induce or disrupt miR-155 regulation and demonstrate that these alleles are selected with
different modes among human populations, to optimize the protein abundance in response to different level of UV radiation. Our findings illustrate the evolutionary plasticity of the microRNA regulatory network in recent human evolution.