Project description:For the filamentous cyanobacterium Anabaena variabilis to grow without combined nitrogen, certain cells differentiate into heterocysts that fix N2, while vegetative cells perform photosynthesis. Much remains unknown on how heterocysts differ from vegetative cells in terms of carbon and energy metabolisms. Microarrays were used to investigate gene transcription patterns in vegetative cells, heterocysts, and filaments of N2-fixing phototrophic, mixotrophic, and heterotrophic cultures.
Project description:For the filamentous cyanobacterium Anabaena variabilis to grow without combined nitrogen, certain cells differentiate into heterocysts that fix N2, while vegetative cells perform photosynthesis. Much remains unknown on how heterocysts differ from vegetative cells in terms of carbon and energy metabolisms. Microarrays were used to investigate gene transcription patterns in vegetative cells, heterocysts, and filaments of N2-fixing phototrophic, mixotrophic, and heterotrophic cultures. Hybridizations used NimbleGen expression array chips (Product no. A4385-00-01, platform accession no GPL15883) designed against the 5,657 ORFs encoded in the A. variabilis genome (GenBank accession no. CP000117). Each ORF was represented by seventeen 60-mer oligonucleotides. Each oligonucleotide was present in four internal replicates. The twenty-seven microarray data files were normalized against each other. Expression array data were analyzed using ArrayStar 3.0 (DNASTAR, Madison, WI).
Project description:Here, we report the transcriptome of Anabaena sp. strain 7120, a cyanobacterium that forms specialized nitrogen-fixing cells called heterocysts. Our data suggests that cyanobacteria frequently have more complex transcripts than thought, with large 5' UTRs, numerous antisense transcripts, and multiple transcriptional start sites or processing sites.
Project description:ChIP analysis unravels an exceptionally wide distribution of binding sites for the NtcA transcription factor in a heterocyst-forming cyanobacterium.