BME Lecture Series: Jeffrey Barrick, UT Austin

Abstract: When we engineer biology, we not only change the properties of an organism, we also alter how it is able to evolve, for better or for worse. My lab has used systems for expanding the genetic code with nonstandard 21st amino acids to address long-standing questions about the optimality of the natural genetic code by performing highly parallel laboratory evolution experiments with bacteriophage T7. We find differences in the extent to which various 21st amino acids neutrally permeate the T7 proteome, and also examples of beneficial mutations that are not possible with the standard genetic code. These results highlight the potential for genetic codes expanded with unique chemical functionalities to improve adaptation. On the other hand, unwanted evolution often makes biological engineering less reliable and less predictable. In particular, takeover of cultures by "cheater" cells with mutations that disrupt an engineered function can be a major problem.

Bio: Jeffrey E. Barrick is an assistant professor of molecular biosciences and a member of the Center for Systems and Synthetic Biology at the University of Texas, Austin. His research group works at the interface of experimental evolution and synthetic biology, exploring why microbial evolvability varies and how it can be engineered. He is the recipient of NIH Pathway to Independence and NSF CAREER Awards. Barrick completed his Ph.D. at Yale University, where he worked with Ronald Breaker on discovering new families of metabolite-binding riboswitches and other structured regulatory RNAs. In his postdoc in the lab of Richard Lenski at Michigan State University, he studied genome dynamics in a 25-year evolution experiment with E. coli.