NSF Postdoctoral Fellowship in Biology for FY 2011

Rohlfs Rori V, Seattle WA

Investigators

Abstract

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2011, Intersections of Biology and Mathematical and Physical Sciences. The fellowship supports a research and training plan in a host laboratory for the Fellow at the intersection of biology and statistics. The title of the research and training plan for this fellowship to Rori Rohlfs is "Developing statistical tools to examine the evolution of gene expression." The host institution for this fellowship is the University of California, Berkeley, and the sponsoring scientists are Drs. Rasmus Nielsen and Sandrine Dudoit. The regulation of the degree to which a particular gene is used, called gene expression, has been proposed as an important mechanism explaining much of species diversity yet a rigorous statistical framework that models gene expression evolution has not yet been established. This research uses the Ornstein-Uhlenbeck process to build a model of the evolution of gene expression. It takes into account the existing phylogeny, relationships between genes and between species, factors limiting constraints on gene expression, and an optimally fit expression level. After demonstrating the model's biological and statistical validity, the research uses a data set of mammalian gene expression, as measured with new RNA-Seq technology. Specific hypotheses regarding the evolution of gene expression levels in mammals are tested. For instance, based on the model, the likelihood ratio test determines if genes expressed in human brain are undergoing rapid expression adaptation along the human species lineage. A goal is to produce an open source software package of the model for broad use in studies of expression evolution across biological disciplines. Training goals include strengthening scientific collaborations and developing and distributing tools that will be accessible widely to the scientific community. Broader impacts include outreach to the public through collaborations with science media and public museums on the underlying causes of differences between species. Educational outreach includes designing and teaching a course at K-12 schools and community colleges.