Team:Vanderbilt/Practices/Interlab
Interlab Study
We saw the iGEM InterLab study as an opportunity for measuring genetic instability as part of the InterLab's wider effort to characterize these BioBrick devices. After cloning and measuring the reporter cassettes to contribute our data to the study, we continued propagating our transformed cells to see how quickly they lost fluorescent signal due to genetic instability. After three attempts of starting long-term measurement experiments, we were unable to propagate fluorescent cells over long periods of time. While we initially believed this to be a technical error, after hearing of a similar study conducted by the University of Texas at Austin's 2015 iGEM team, it turns out that our results were actually similar to theirs, and that the lack of fluorescence beyond a couple days was in face due to rather extreme genetic instability.
Hence, our own long-term study based on the InterLab reporter cassettes revealed a striking example of how evolutionary instability can lead to rapid loss of function of even the most rudimentary circuit element. Just as interestingly, our prior results looking at RFP-expressing cells over nearly month-long time spans did not exhibit this same dramatic loss of function. This is a clear indication of a mutation hotspot at work, and the University of Texas team has proposed that transposon hotspots may be the culprits in this case. Finding and eliminating hotspots like these with our optimization software may be able to achieve differences as pronounced as that between these highly-unstable InterLab cassettes and our RFP testing cassettes.
