Microbiology/Cell Biology, bacteria polarized growth, chromosome, imaging

The integration of DNA replication with cell division is fundamental to the growth of any organism. This project is aimed at understanding the coordination of chromosome segregation with germination in the bacterium, Streptomyces coelicolor. Streptomycetes are the most commercially important bacteria, producing over 70% of antibiotics. They are also morphologically unusual, growing by means of multinucleate vegetative hyphae, before differentiating to form unigenomic spores (1). As a result, comparison of chromosome segregation with those of other bacteria will shed light on the fundamental practices shared between all prokaryotes and may act to identify new drug targets in the related pathogens Mycobacterium tuberculosis and Corynebacterium diptheriae.

In recent years, the use of GFP in has revolutionized Cell Biology. We have tagged the origin of replication (oriC) of the S. coelicolor chromosome with GFP using a fluorescent reporter operator system (2). In this system, oriC is tagged with a tandem DNA array of 120 tet operators. Consequently, binding of the cognate DNA-binding protein (TetR, fused to GFP) to these sites can be visualised by fluorescence microscopy.  We have generated movies of oriC movement in order to characterise chromosome segregation during growth and development. During this project we will determine the effect on oriC movement of deleting genes whose protein products have been detected during the early stages of germination(3).

Microbiology, molecular biology, fluorescence microscopy, image tracking

1.         Flardh, K., and Buttner, M. J. (2009) Streptomyces morphogenetics: dissecting differentiation in a filamentous bacterium. Nature Reviews Microbiology 7, 36-49

2.         Lau, I. F., Filipe, S. R., Soballe, B., Okstad, O. A., Barre, F. X., and Sherratt, D. J. (2003) Spatial and temporal organization of replicating Escherichia coli chromosomes. Molecular Microbiology 49, 731-743

3.         Strakova, E., Bobek, J., Zikova, A., Rehulka, P., Benada, O., Rehulkova, H., Kofronova, O., and Vohradsky, J. (2013) Systems insight into the spore germination of Streptomyces coelicolor. Journal of proteome research 12, 525-536