BACTERIAL PATTERNS · Network analysis of bacterial multi-cellular patterning
FP7 — People (Marie Curie Actions)
- Duration
- 2010-10-01 → 2014-09-30
- EU contribution
- €100,000
- Participants
- 1
- Scheme
- MC-IRG
Lines connect the coordinator with its partners.
Results in brief
Network analysis of bacterial multi-cellular patterning
The specific aims of the grant were to study biofilm formation in the model Gram positive bacteria Bacillus subtilis by combining gene expression analysis and genetics with a novel light activation system. The logic of the proposal was that local activation of gene expression in a specific region and the ability to read gene expression reporters, will enable us to infer causality of cell non-autonomous and spatial interaction and that combining these measurments with mutant analysis will enable us to better infer community behavior of this model organism. The project therefore contained two paths, which were supposed to converge at the middle of the project: i) establishing the light-activation system in B. subtilis and constructing light activated constructs, and ii) studying gene expression and biofilm formation in mutants. Unfortunately, we have not been able to perform the first (and most novel path), the construction of light activation system. This part proved more problematic than expected. After significant exploration, we hypothesize that a crucial phosphorylation step in the light activation system is inhibited by an unidentified phoaphatse. We were therefore unable to perform the crucial part of the project. Nevertheless, we were able to continue with the second (more conservative) path of studying biofilms using genetics and gene expression studies. We have been able to obtain multiple results on the genetics of biofilm formation in B. subtilis. A first manuscript on the subject has been recently accepted to the journal of bacteriology, while other related works are under continuous work. In the accepted manuscript we have identified a role in biofilm formation for a novel quorum-sensing (signaling) system called rapP-phrP. We show that this system was not identified before due to a mutation in the strain used by other researchers. Once this mutation is corrected, we showed that inter-cellular signaling is formed and substantially affect biofilm formation. In the yet unpublished works, we have used a genetic screen approach to identify multiple novel regulators of biofilm formation, and specifically for the production of the surfactant surfactin. We were also able to find conditions in which the coupling between biofilm formation and sporulation is broken, allowing us to better study the genetic regulation of this coupling process.
Data: CORDIS, © European Union
Project objective
Defining the mechanisms by which cells cooperate to form complex structures and a common function is a fundamental problem in both developmental biology and socio-biology. Cooperative interactions among bacteria are a relatively simple, yet medically important, model system where this problem can be explored in its full generality. Specifically, bacterial growth on surfaces is often accompanied by formation of complex patterns and increased resilience to diverse external insults. The importance of multiple co-existing cellular differentiated states and of specific cell signaling processes, to spatial patterning and development of bacterial communities has been demonstrated in several systems, including the well-characterized microbe, Bacillus subtilis. However, the nature of these interactions and the way they control the spatial organization of differentiation and patterning is unclear. Specifically, we do not understand (1) when and where are genes and cell fates expressed? (2) What is the spatial organization of cell fates? (3) How does the interaction between fates give rise to spatial order? Here, we suggest addressing these questions by utilizing a novel light-activated gene expression system. This will be used to control the spatial and temporal gene expression profile of a library of patterning-related genes. Time-lapse fluorescence microscopy will be used to monitor the dynamic expression of relevant reporters in wild-type and spatially perturbed backgrounds. We will use mathematical modeling to integrate the results into a predictive model of pattern formation and community development. My previous experience in mathematical modeling of spatial systems, and experimental background in developmental genetics, microbiology and advanced microscopy provides a well suited background to successfully pursue this important problem.
Original text from CORDIS.
Participants
- TEL AVIV UNIVERSITY · Tel AvivCoordinatorIsrael
Links
Data: CORDIS, © European Union