Sugata Roy Chowdhury
Graduate Student

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Members of the Proteobacteria have a characteristic dormant stage in their life cycle, called cyst stage. These cells when grown on nutrient deficient medium, switch from their active stage to resting form as part of their life cycle. The cysts are metabolically quiescent forms and are capable of surviving extreme drought conditions and are also resistant to heat. Detailed genetic studies about the transition of vegetative cell to encystment cycle in these gram-negative proteobacteria have not been done. I have chosen the phototrophic bacteria, Rhodospirillum centenum , as the model organism as its genome of this bacterium has been completely sequenced and annotated. Using DNA chip array technology, I want to identify the genes that are up regulated upon shifting of vegetative cells to cyst inducing conditions. Also, isolate and analyze mutants that are altered in the cyst inducing condition. This study will help to establish the first detailed analysis of the factors in regulatory circuits that are controlling the formation of metabolically dormant cysts in a proteobacterial species. Furthermore, the study will help us to understand the mechanisms used by a bacterial cell to respond to the changes in the environmental growth conditions like specific nutrient deficiency in the culture medium.