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Published on: January 18, 2014
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Sequential evolution of bacterial morphology by co-option of a developmental regulator
Chao Jiang1, Pamela J B Brown2, Adrien Ducret1
1Department of Biology, Indiana University, Bloomington, Indiana 47405, USA.
Nature
|January 28, 2014
Summary
Bacterial cell shape evolution is driven by changes in protein function and localization. A study on stalk positioning in bacteria reveals how protein co-option and modularity facilitate morphological transitions.
Area of Science:
- Microbiology
- Evolutionary Biology
- Cell Biology
Background:
- Bacterial morphology exhibits significant diversity, yet the evolutionary mechanisms driving these shape changes remain largely unknown.
- The synthesis and positioning of cell envelope extensions, such as stalks, vary considerably across bacterial species.
- Understanding these variations is crucial for deciphering the evolution of bacterial form.
Purpose of the Study:
- To investigate the molecular mechanisms underlying the evolution of bacterial cell shape, specifically focusing on stalk positioning.
- To explore the role of the developmental regulator SpmX in determining stalk location in the genera Caulobacter and Asticcacaulis.
- To elucidate how changes in protein function and localization contribute to morphological transitions.
Main Methods:
- Comparative analysis of stalk synthesis and positioning in Caulobacter and Asticcacaulis.
- Investigating the function and subcellular localization of the SpmX protein in different bacterial species.
- Studying the evolutionary history and functional changes within specific regions of the SpmX protein.
Main Results:
- The developmental regulator SpmX was found to be co-opted in Asticcacaulis to specify subpolar or bilateral stalk synthesis.
- Stepwise evolution of a specific region of SpmX led to altered protein function and localization, driving sequential changes in stalk positioning.
- This demonstrates a direct link between protein evolution and morphological diversification.
Conclusions:
- Changes in protein function, co-option of existing regulators, and modular protein evolution are key drivers of bacterial morphological transitions.
- The evolutionary principles governing morphological changes in bacteria are comparable to those observed in multicellular eukaryotes.
- This study provides insights into the evolution of diverse bacterial shapes through the modification of developmental pathways.
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