This project will produce a genome sequence of the fresh-water filamentous cyanobacterium Fremyella diplosiphon UTEX 481. Pyrosequencing on the 454 platform will be used to sequence the 12 million base pairs of this genome, one of the largest known in bacteria. These data will be used to compile a complete description of the genes contained in this bacterium, to reveal important physiological and regulatory mechanisms involved in prokaryotic responses to changes in ambient light color. The genetic content will also be compared to other sequenced cyanobacterial species and photosynthetic bacteria, to provide a broad picture of the evolution of photosynthesis and the cyanobacterial species. F. diplosiphon is a well-developed model organism that has been used to advance understanding of how microorganisms sense and respond to their environment for forty years. Initially selected and cultivated for its ability to sense and respond to changes in ambient light color conditions, the response of its photosynthetic light harvesting antennae to light color changes is now the best understood of any organism. F. diplosiphon is used to study a wide range of additional physiological and biochemical processes such as �proteome remodeling� in response to nutrient limitation. It is also used to study developmental responses such as gas vesicle formation and phototropism, the ability of an organism to grow in a specific direction in response to the presence or absence of unilaterally applied light. Important biochemical processes are also studied in this species, including chlorophyll and bilin biosynthesis and F. diplosiphon is one of the few prokaryotes that produces both cAMP and cGMP in signal transduction, key signalling molecules in plants and animals.

Light responses are important in the process of photosynthesis, which played a critical role in the evolution of our planet, and are necessary for the maintenance of nearly every ecosystem. Moreover an understanding of these physiological processes can contribute to the develop of bioenergy sources.