Abstract

We are using small RNA to build decision-making devices, Ratio Sensor and Comparator,which process two independent inputs into detectable output.

What our decision-making device could do?

Our decision-making device aims at processing the concentration change of nitrate or phosphate into visible buoyancy increase, to this end, we facilitate two well studied promoters(Plac and Ptet) and GFP to construct a quantitative test platform, where GFP mRNA concentration will be monitored indirectly through fluorospectro photometer.Of course,IPTG and aTc serve as two substitute inputs instead of nitrate and phosphate. Comparator recognizes the difference of two inputs quantitatively ,while ratio sensor could senses a particular ratio between two inputs.

How?

Both comparator and ratio sensor facilitate a 3-ternary system composed of two small RNA and GFP mRNA.They are generated from plasmid and then diffuse in cytosol ;considering RNA pairing reaction as chemical reaction,we will see the probability of collision is determined by their concentration,and the probability of pairing after collision is determined by their affinity(that is reaction constant k). The concentration change of aTc and IPTG in media leads to the transcription rate change of small RNA(αs)in this 3-ternary system, we hope the interactions between three RNA will lead to interesting behaviours of our devices like sensing the difference between two inputs quantitatively(Comparator) or the ratio of two inputs(Ratio senor).