(126g) A Synthetic Ecological System for Pattern Formation
AIChE Annual Meeting
Monday, October 17, 2011 - 2:40pm to 3:00pm
Synthetic biology is the design and construction of new biological entities such as proteins, genetic circuits, and cells or even the redesign of existing biological systems. In my work, I design and construct a synthetic ecological system to study how simple local rules lead to global pattern formation.
In nature, programmed cell death is often used to remove excess cells, as is seen in embryo, finger, and brain development, sea urchin metamorphosis, and plant immune responses. Within the context of synthetic biology, coordinating cell death and survival artificially will enhance our understanding of natural systems and our ability to engineer complex cellular patterns. In addition, the ability to precisely regulate cell density is essential for numerous medical and industrial applications. To explore coordination of cell death and survival and pattern formation, I implemented a synthetic ecological system with the following game rules: 1) cells die when they are in an overpopulated environment due to overpopulation (too many neighbors); 2) cells die when they are in solitude (too few neighbors); 3) cells survive and proliferate only when there are an intermediate number of neighbors. By changing the underlying local interaction rules, interesting 2D global patterns emerge after repeated rounds of cell death and survival. This work provides an important platform for understanding how local rules dictate complex global behavior.
In order to achieve this goal, I implement a genetic circuit with three modules into yeast. 1) The first is an artificial cell-to-cell communication module that detects neighboring cell density using a small diffusible signal molecule; 2) the second is a low threshold killing and rescuing module that kills cells at low signal levels but prevents cell death at high signal levels; and 3) the third is a high threshold killing module that kills cells at high levels of signal molecules.