Elements of the heterocyst‐specific transcriptome unravelled by co‐expression analysis in Nostoc sp. PCC 7120

摘要: Nitrogen is frequently limiting microbial growth in the environment. As a response, many filamentous cyanobacteria differentiate heterocysts, cells devoted to N2 fixation. Heterocyst differentiation under control of master regulator HetR. Through characterization HetR-dependent transcriptome Nostoc sp. PCC 7120, we identified new candidate genes likely involved heterocyst differentiation. According their maximum induction, defined E-DIF (early differentiation) and L-DIF (late genes. Most known be critical aspects or function were also classified into these groups, showing validity approach. Using fusions gfp, verified heterocyst-specific transcription several found genes, antisense transcripts potentially trans-acting sRNAs. comparative sequence analysis promoter regions, noticed prevalence previously described DIF1 motif second motif, called DIF2, other promoters cluster. Both motifs are widely conserved heterocystous cyanobacteria. We assigned alr2522 as third member, besides nifB nifP, CnfR regulon. The elements here interest for understanding cell differentiation, engineering biological nitrogen fixation production O2 -sensitive molecules