Quantification of gas vesicle gene expression in single filaments of cyanobacteria

• Applicant: Dr. Sven Becker
• Subject Area: Microbial Ecology and Applied Microbiology
• Term: from 2003 to 2005
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5417145

A change of environmental conditions like temperature of light can cause a change in the buoyancy of cyanobacteria (e.g. Planktothrix) due to changes in the formation of gas vesicles, which account for about 10% of total cell protein. However, the molecular mechanisms, especially the transcription of gas vesicle genes, that control buoyancy, are not understood. The aim of this project is to investigate in single filaments of Planktothrix spp. switches in the expression of different length of gvpC genes within the same operon. Length variants of gvpC code for the GvpC protein in the protein shell of gas vesicle and they cause Planktothrix strains to produce gas vesicles of a specific diameter and, thus, of a specific strength. This allows a selection of different gas vesicle genotypes in lakes of different depth. By the application of quantitative real-time reverse transcription PCR, the gas vesicle gene expression in single filaments of Planktothrix spp. from laboratory cultures and lake water samples will be determined at differend conditions. The consideration of transcription rates in models for the position of cyanobacteria on vertically decreasing light gradients in lakes will lead to new insights into the depth selection of cyanobacteria.

• DFG Programme: Research Fellowships
• International Connection: United Kingdom
• Cooperation Partner: Professor Dr. Anthony E. Walsby