A Synthetic Ecological System for Pattern Formation

This project aims at programming yeast cell life and death, and thereby study pattern formation, by integrating a synthetic genetic circuit into yeast cellular machinery. This engineering approach can be applied to cell density control in biotechnology industry, pattern formation in tissue engineering, and cell fate control in cancer therapy.

Project Design -- The fate of yeast cells is programmed based on the following rules:

(1) When there are too few neighbors, cells die due to loneliness;
(2) When there are too many neighbors, cells die due to overpopulation;
(3) Cells survive only when the number of neighbors falls within a narrow bandpass.

To implement the project goals, three biological modules are designed: 1) A quorum sensing module, which senses neighboring cell population density. Depending on the latter, it can activate a downstream killing or rescuing mechanism; 2) A low threshold killing module, which kills yeast cells when the population density is below a minimum threshold level, and prevents death at intermediate levels;; and 3) A high threshold killing module, which kills yeast when the population is above a maximum threshold level. Each module is systematically characterized, modularized and optimized before it is integrated into a complex genetic network to implement the project design goals. Finally, the synthetic genetic circuit is implemented on solid media, which couples diffusion into the system to facilitate the study of pattern formation mechanics.