Format

Send to

Choose Destination
Annu Rev Genet. 1996;30:59-78.

Heterocyst formation.

Author information

1
MSU-DOE Plant Research Laboratory, East Lansing 48824, USA.

Abstract

Heterocysts are microaerobic, N2-fixing cells that form in a patterned array within O2-producing filamentous cyanobacteria. Structural features of heterocysts can be predicted from consideration of their physiology. This review focuses on the spacing mechanism that determines which cells will differentiate, and on the regulation of the progression of the differentiation process. Applicable genetic tools, developed primarily using Anabaena PCC 7120, but employed also with Nostoc spp., are reviewed. These tools include localization of transcription using fusions to lux, lac, and gfp, and mutagenesis with oriV-containing derivatives of transposon Tn5. Mature and developing heterocysts inhibit nearby vegetative cells from differentiating; genes patA, devA, hetC, and the hetMNI locus may hold keys to understanding intercellular interactions that influence heterocyst formation. Regulatory and other genes that are transcriptionally activated at different times after nitrogen stepdown have been identified, and should permit analysis of mechanisms that underlie the progression of heterocyst differentiation.

PMID:
8982449
DOI:
10.1146/annurev.genet.30.1.59
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Atypon
Loading ...
Support Center