RNA as logic gates

We have our departmental seminars every Tuesday. Yesterday's talk was one of the most impressive I have ever seen. The professor was making logic gates in cells using RNA molecules. Unlike in proteins, if sequence of an RNA molecule is known, you can predict its structure using available algorithms. From the structure, you can determine how the molecule will respond to a ligand. So, the Professor's lab was attaching RNA molecules of known response to different ligands to genes. In one conformation, the RNA molecule suppressed the gene and in another it did not. And so by introducing some concentration of a ligand, you can in principle have an on-off mechanism. This idea can be used to make different logic gates. The interesting part was that it was not a chimerical hypothesis, but a real experimental work. We were shown experimental evidence that the logic gates can be made and do work as desired! Quite amazing. Another interesting thing was that the speaker was not an old, senile-looking professor but a young, pretty girl who anyone would mistake as a graduate student.

Earlier during the day, I had the opportunity to have lunch with her. It is a new thing in our department that the invited speaker is taken to lunch by some grad students. I was not interested initially, but there was one open slot and the dept secy asked me to take it (somehow I am a default inclusion if there is a need of a grad student for any such extraneous thing in our Dept). Well, I enjoyed the lunch though. During the lunch, our discussion mainly revolved around how to prepare applications for faculty positions, as she had done it only some 5 odd years back. And, she mentioned more than once that the kind of applications they get at their university for faculty positions are of very high quality and sometimes makes her wonder how her application got through. And, more than once the thought crossed my mind that there could be some favorable bias towards a pretty, young girl. And when it did, I smiled and nodded. But, later during the day, she completed bowled  us over with her presentation. I was guilty of my prejudice but she had seeded it with her humbleness...