Identifying the design principles of flagella biosynthesis programs in single bacteria during deep stationary phase
Final Report Abstract
Bacteria are extremely versatile organisms that can rather easily adapt to changing environments. We isolated an interesting mutant candidate for further investigation from an E. coli culture that was growing for several months without the addition of new nutrient sources. The mutated protein, maoP, is a poorly understood and barely studied chromosome organization protein of E. coli. E. coli normally expresses flagella, multicomponent organelles used for locomotion, counterintuitively under poor growth conditions. Interestingly, a mutation in maoP leads to enhanced expression of flagella under rich growth conditions, thereby reprogramming the underlying regulatory network in an unknown manner. The synthesis of flagella is a highly organized and tightly regulated process. It was shown before that the genes within the network hierarchy are stochastically activated in pulses in E. coli with longer inactive states. First results obtained by microfluidics indicate that only the amplitude of the pulses but not their frequency is affected by the maoP mutation, which hints against a change in the transcriptional dynamics. We used NGS to identify the mutation and verified the observed phenotype by flow cytometry, epifluorescence microscopy and transcriptomics. Further experiments are required to unravel the underlying mechanism that leads to the enhanced flagella expression under the given conditions. Especially understanding why and how a macrodomain organization protein is involved in this process and whether other networks might be affected would be of particular interest.
