Synthetic Biology is a field that is changing both how we understand and engineer biology. Instead of adding/deleting one gene at a time the way we've done using genetic engineering techniques for 30 years, we are learning how to manipulate collections of genes to program entirely new behaviors in organisms that they do not normally do. These new behaviors could be the engineered production of fuels or medicines, or the ability to act as biosensors that detect different environmental conditions or treat disease.
My Ph.D. mainly focused on developing a way to engineer bacteria to produce synchronized dynamic behavior across a population of cells. Up until this point, most work had focused on engineering single cells, but coordinated behavior, although quite common in nature, is challenging to genetically program in the lab from the bottom-up. To do this, we hijacked a genetic system called 'quorum sensing' from naturally occurring bacteria, which they use to communicate with one another and trigger behaviors such as virulence and biofilm development. Putting together pieces of DNA to encode this behavior we built the design (below) and created microscope 'movies' of bacteria transformed with this system.
Below is a schematic of how we wired these different genes together. There is more scientific detail in the captions, but for the average reader, this Nature produced video gives the best introduction to how we synchronized bacterial behaviors.
Arthur Prindle, a graduate student at UCSD, extended this further by synchronizing not just individual bacteria, but colonies of bacteria to each other via gas communication (see Prindle Nature 2011 or read more here). In this movie below, each little square represents a few thousand of bacteria that you saw in the movies above. This was a significant advance, not only because the scale of synchronization was increased, but also because these bacteria were programmed to flash at different frequencies according to how much Arsenic they sensed in their growth chambers. Thus, they could act as biosensors to warn against groundwater contamination from harmful chemicals.
In addition to the interesting visual science behind our work, I found that these microscopic movies were engaging to a wide audience and I started using them for science-outreach at demos, museums, and presentations. Below is a compilation of these movies in different forms.