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Multicellularity in a heterocyst-forming cyanobacterium: pathways for intercellular communication
Vicente Mariscal1, Enrique Flores
1Instituto de Bioquímica Vegetal y Fotosíntesis, C.S.I.C. and Universidad de Sevilla, Américo Vespucio 49, E-41092, Seville, Spain. vicente.mariscal@ibvf.csic.es
Advances in Experimental Medicine and Biology
|June 10, 2010
Summary
Anabaena filaments feature two cell types: vegetative cells and heterocysts. These cells exchange nutrients and signals through a shared periplasm and protein complexes, facilitating multicellular life.
Area of Science:
- Microbiology
- Cell Biology
- Biochemistry
Background:
- Filamentous cyanobacteria, like Anabaena sp. strain PCC 7120, represent simple multicellular prokaryotes.
- In nitrogen-limited conditions, Anabaena filaments differentiate into two interdependent cell types: vegetative cells and heterocysts.
- Vegetative cells perform photosynthesis and provide carbon to heterocysts, while heterocysts fix atmospheric nitrogen and supply nitrogenous compounds.
Purpose of the Study:
- To explore potential mechanisms for intercellular communication and metabolite exchange between vegetative cells and heterocysts in Anabaena.
- To understand the structural basis for nutrient and signal transfer in this model organism for multicellularity.
Main Methods:
- Review of existing literature on Anabaena cell structure and function.
- Analysis of proposed models for intercellular transport pathways.
Main Results:
- Two primary pathways are discussed for intercellular exchange: a continuous periplasmic space and specialized septal protein complexes.
- The periplasm may facilitate diffusion of molecules between cells.
- Septal complexes could enable direct, regulated transfer of small molecules.
Conclusions:
- The continuous periplasm and septal protein complexes are key structural features enabling metabolic and regulatory coordination in Anabaena filaments.
- Understanding these pathways is crucial for comprehending the evolution and function of multicellularity in prokaryotes.
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