Research Interests

All life begins with a single cell. How can a community of cells—e.g., human tissues, microbial biofilms, and cancerous tumors—produce collective properties not shared by any one individual? Understanding how cells communicate is critical to understanding this developmental process of unguided design. Communication arises from the combination of genetic programming within cells and physical interactions between cells that result in their arrangement in space and time. Genetic programming drives the decision-making processes of individual cells. Spatiotemporal organization applies logic to the coordination of these decisions between cells by constraining the sets of interacting partner cells as a function of time. Dissecting this interplay will grant insights into the fundamental forces that shape the diversity of life on Earth, from bacteria to humans.

My Ph.D research with Jeff Hasty focused on engineering approaches to building genetic circuits, with a particular emphasis on their coupling across space and time. One insight from this work was how macroscopic synchronization can arise from the synergistic combination of two differently diffusing messengers—strong local coupling by quorum sensing and weak global coupling by H2O2 vapor (see videos below). My postdoc research with Gurol Suel involves biological and biophysical approaches to understanding how the unique properties of multicellular communities arise, taking the bacterial biofilm as a model system. In particular, we are investigating how collective dynamics during biofilm development can give rise to community properties such as drug resistance.

Research Highlights

(1) A sensing array of radically coupled genetic 'biopixels'. [Nature 2012]

I used synergistic modes of communication—quorum sensing via dissolved AHL and redox signaling via H2O2 vapor—to enable the synchronization of genetic clocks across centimeter length scales. I used this platform to construct an LCD-like macroscopic "biopixel" array used to sense arsenic via modulation of the oscillatory period. This work received substantial attention including an F1000 evaluation, Nature News & Views commentary, and media coverage from MSNBC, CNET, L.A. Times, Popular Science and others.

(2) Rapid and tunable post-translational coupling of genetic circuits. [Nature 2014]

I used competitive coupling to post-translationally link two independent genetic clocks across the single-cell, colony, and multi-colony scales. Using this platform, I constructed a multispectral encoding circuit whereby frequency-modulated oscillations from both clocks are combined into a single time series, thus enabling the extraction of the dynamics of multiple underlying networks via the measurement of a single reporter. In addition, through integration with host signaling processes, I used the clock network to uncover novel regulation in the host stress response to H2O2.