Farren Isaacs - Design, Synthesis and Control of Genetic and Genomic Systems
Thursday's other talk was in the Bioengineering department at the UW. I feel rather stupid for having taken this long to discover this department and its seminar series, since they have quite a few interesting talks each semester. Anyway, the presenter was a faculty candidate from the Center for Computational Genomics at Harvard, giving an overview talk about his work on engineering biological systems; for me this was probably an appropriate first talk to go to in the series.
To set the scene, we were given a general overview of gene regulation, mainly making a point that I've found myself making a lot recently: that it's not as simple as here is the gene for XYZ
, so much as a complex network of interacting parts. Then Isaacs grounded his interest in engineering such a system with two practical applications: more efficient creation of biofuels, and the production of chemicals needed for medicine (I'm guessing he meant things engineering organisms to produce insulin).
His approach to bioengineering is quite different from others I have read or heard about. Most genetic engineering work seems to focus on directly inserting or removing sequences from DNA by using vectors such as viruses or phages to splice the molecule. Instead, Isaacs engineers the RNAs that are involved in DNA maintenance and transcription, using changes in the structure of the RNA to control how it manipulates the DNA string. This in turn can suppress expression of a targeted section of the DNA. This seems to be useful because a given engineered RNA can be given great specificity in terms of what DNA sequence it will alter, allowing very targeted up- or down- regulation of specific genes, and because the regulation achieved can be altered dynamically rather being a one-shot process.
After the theoretical background, Isaacs went on to describe some quite impressive work on modifying the E.coli genome. The technique is currently being tested as a way of giving the modified organism resistance to specific viruses; ultimately the aim seems to be to produce bacterial drug factories
that will secrete useful compounds as a by-product of their metabolism.
Comments
It sounds as though the RNA can up or down regulate existing DNA in the organism's genome.
When one wants the organism to produce some new protein, does the DNA of the organism need to be modified as well?
I wasn't totally clear on this, but my impression was that the RNA could actually be engineered to make fairly substantial changes in the DNA it was editing.