OK, this one is just too great not to post. David Liu's group at Harvard managed to "weaponize" Darwin's evolution theory against insects:
http://blogs.sciencemag.org/pipeline/archives/2016/05/16/evolution-in-action-literallyThat's one of the most awesome bioengineering techniques I've seen, and with enormous potential, too. In a nutshell, it's possible to set up a system in which a bacteriophage's ability to reproduce depends on the protein (and its functionality, of course) you want it to make. Derek Lowe explains it best:
Here’s how that works: the M13 bacteriophage have a specific surface protein, pIII, that they need for their progeny to be infectious. In this case, they’ve had that gene stripped out of their sequence, but it’s been added instead to the E. coli cells that they’re going to be infecting. That gene is set up, on an accessory plasmid (AP) downstream of a promoter that’s tied to the protein-protein interaction that you’re trying to evolve – so only when some protein can bind to its target up there will pIII get produced. That protein is what the phage are going to have to evolve to keep themselves reproducing – they infect the bacteria with a selection plasmid (SP), and if that plasmid DNA can generate a protein that starts the pIII production machinery, then they can get enough pIII for their progeny (being produced inside the infected bacterium) to be infectious in turn. The bacteria also have a mutagenesis plasmid (MP), arabinose-driven, that bumps up the rate of error-prone DNA copying, to keep a mutagenic foot down on the evolutionary gas pedal.
And here’s the final trick: the bacteria are in a “lagoon” vessel, and are being continuously dripped in (and the contents of the lagoon are being similarly slowly drained out. You tweak these flow rates to fit the rate of phage mutations, so that they’re in a constant fitness race. If they can evolve proteins to get their pIII protein and go on for another generation faster than they’re being diluted out of the lagoon, they’ll keep going. Otherwise, out they go. You have to play around with these, of course, so that you’re giving them a fair shot in their c. 20-minute lifespan: run things through too quickly, and the phage won’t have a chance, but if you do it too slowly they have no incentive to better themselves.
Using this, you could "evolve" protein variants that work on organisms resistant to the basic form. So far it seems to work with the Bt protein (a common insecticide that insects are evolving resistance to), but I can see this being of use for evolving antibiotics that work on resistant bacteria. And if they evolve to be resistant to
those, we could evolve new variants again.
