Emerging Frontier 03: Functional Analyses of the Genome of the Phenotypically Complex, Multicellular Cyanobacterium Nostoc Punctiforme

点击翻译按钮获取中文摘要

The experimental core of this project is functional genomic analyses of the cyanobacterium Nostoc punctiforme. The shotgun sequencing of the 9.25 Mbp genome of N. punctiforme has been completed and an annotated database is available at http://www.jgi.doe.gov . N. punctiforme has an extraordinarily wide range of ecological niches, physiological properties and cellular developmental alternatives, including the unusual ability of fixing nitrogen in both free-living and plant-associated symbiotic growth states. Nitrogen fixation occurs in terminally differentiated cells called heterocysts. In addition to heterocysts, N. punctiforme vegetative cells can transiently differentiate into resting cells termed akinetes and motile filaments called hormogonia. The working hypothesis is that the regulatory elements and pathways governing cellular differentiation alternatives and symbiotic interactions of N. punctiforme uniquely evolved in cyanobacteria. Therefore, functional, in addition to computational, analyses are required to identify the developmental genetic elements and regulatory circuits present in the genome. Understanding how these circuits are integrated in N. punctiforme has implications on the evolution of developmental pathways in complex organisms. This project will utilize high throughput genomic methodologies of global gene expression assays, using DNA microarrays, and mutagenesis. The resources generated, including all of the individually amplified genes present in the genome, will be made available to the national and international cyanobacterial community. Researchers at the level of principle investigators, technicians, postdoctoral fellows, graduate and undergraduate students, will interact in developing and applying these new methodologies to this complex cyanobacterium; thus, the project affords an integrative training opportunity.