Team:NJU-QIBEBT

Chemtaxis , which can make strains move, interest us this time. By reprogramming the strain (CL-1), which lacks the CheZ gene, we can create mathematical patterns. CheZ gene belongs to chemotaxis family of E.coli. Protein CheZ can dephosphorylate CheY-P, one that allows E.coli swimming smoothly. The ΔCheZ bacteria can’t dephosphorylate CheY-P, so the strain won’t motile until CheZ is involved in. That means the motility of E.coli can be precisely control by stimulus (e.g. IPTG). We try to construct logic gene circuits to make E.coli recognize environmental stimulation, thus by utilizing the controlled chemotaxis which named pseudotaxis we could command bacteria to form patterns such as ellipse, hyperbola and so on.

The intrinsic motivation that drive us striving for the above project is that we want to simulate the process of stem cell differentiation. In the organs development, stem cells differentiate while aggregate together to form heart, liver and kidney what have precise shapes. Perhaps some mathematical principles that govern the differentiation process. By simulating differentiation, we want to get a closer understanding of the differentiation process. However, E.coli can’t sense as much stimulus as stem cell, we intend to utilize RNA aptamers what has the potential to response to almost all stimulus to cover that shortage. Thus, we can get a more precise stimulation.

Besides, we try to utilize pseudotaxis to accomplish some experimental meaning. As far as we know, the motile ability is proportional to the amount of protein CheZ in certain range. By measuring the average chemotaxis distance, we will get a precise evaluation on the RBS efficiency that is evaluated by fluorescence strength previously.