Jeff Hasty, PhD
Engineered Genetic Clocks: From Clocks and Biopixels to Stealth Delivery
University of California, San Diego
Departments of Molecular BIology and Bioengineering, BioCircuits Institute
This talk will focus on our ongoing development of genetic oscillators along with recent progress in transitioning to applications related to drug delivery. I will first summarize our understanding of design considerations; we have found that a small time delay and enzymatic protein decay are crucial in the construction of a core oscillator with simple negative feedback, while positive feedback serves to regularize intracellular oscillations and increase the parameter space for cycling. I will then describe clock synchronization using both autoinducer and redox signaling as quorum sensing mechanisms. Microfluidic devices are used to show the collective synchronization of sub-millimeter colonies, while spatiotemporal waves are observed at millimeter scales due to limits set by the diffusive speed of the autoinducer molecule. I will then show how the synergistic coupling of redox and autoinducer signaling can be used to synchronize thousands of "biopixel" colonies over centimeter length scales. I will conclude with recent work on engineering bacteria for the stealth and pulsatile delivery of gene products to tumors.
Jeff Hasty received his Ph.D. in physics from the Georgia Institute of Technology in 1997, where he worked with Kurt Wiesenfeld. He was a postdoc with Jorge Vinals at the Supercomputing Research Institute ('97-'98), and a postdoctoral fellow with Jim Collins in the Applied BioDynamics Lab at Boston University ('98-'01). Somewhere during his postdoctoral stay at Boston University, he mutated into a hybrid computational/molecular biologist. He is currently at the University of California, San Diego, where he is a Professor in the Departments of Molecular Biology and Bioengineering, and the Director of the BioCircuits Institute. His main interest is the design and construction of synthetic gene-regulatory and signaling networks.