Abstract
We have quantitatively modeled heterocyst differentiation after fixed nitrogen step-down in the filamentous cyanobacterium Anabaena sp. PCC 7120 without lateral inhibition due to the patterning proteins PatS or HetN. We use cell growth and division together with fixed-nitrogen dynamics and allow heterocysts to differentiate upon the local exhaustion of available fixed nitrogen. Slow transport of fixed nitrogen along a shared periplasmic space allows for fast growing cells to differentiate ahead of their neighbors. Cell-to-cell variability in growth rate determines the initial heterocyst pattern. Early release of fixed nitrogen from committed heterocysts allows a significant fraction of vegetative cells to be retained at later times. We recover the experimental heterocyst spacing distributions and cluster size distributions of Khudyakov and Golden [Khudyakov, I.Y., Golden, J.W., 2004. Different functions of HetR, a master regulator of heterocyst differentiation in Anabaena sp PCC 7120, can be separated by mutation. Proc. Natl. Acad. Sci. U. S. A. 101, 16040-16045].
Original language | English (US) |
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Pages (from-to) | 427-434 |
Number of pages | 8 |
Journal | Developmental biology |
Volume | 312 |
Issue number | 1 |
DOIs | |
State | Published - Dec 1 2007 |
Externally published | Yes |
Keywords
- Anabaena
- Computational modeling
- Diazotrophic
- Differentiation
- Filamentous cyanobacteria
- Fixed nitrogen
- Growth and division
- Heterocyst commitment
- Lateral inhibition
- Pattern formation
ASJC Scopus subject areas
- Molecular Biology
- Developmental Biology
- Cell Biology