Chimeric aggregative multicellularity in absence of kin discrimination
Michael L Weltzer1, Jack Govaerts1, Daniel Wall1
1Department of Molecular Biology, University of Wyoming, 1000 E University Avenue, Laramie, WY, USA.
Biorxiv : the Preprint Server for Biology
|December 16, 2024
Summary
Myxococcus xanthus uses the type VI secretion system (T6SS) to distinguish kin from non-kin, preventing genetic conflict. This mechanism ensures the formation of monoclonal fruiting bodies during starvation-induced development.
Area of Science:
- Microbiology
- Evolutionary Biology
- Bacterial Social Behavior
Background:
- Aggregative multicellularity is a cooperative strategy in microorganisms like Myxococcus xanthus.
- This strategy faces challenges from genetic conflicts and cheaters, threatening social stability.
- Natural M. xanthus fruiting bodies typically consist of clonemates, suggesting kin recognition mechanisms.
Purpose of the Study:
- To investigate the mechanisms of kin recognition during Myxococcus xanthus development.
- To determine if the type VI secretion system (T6SS) plays a role in kin discrimination.
Main Methods:
- Co-culturing two distantly related M. xanthus strains under vegetative and starvation conditions.
- Observing strain segregation and interactions using wild-type (WT) and T6SS knockout strains.
- Analyzing fruiting body composition (monoclonal vs. chimeric) after co-culture.
Main Results:
- Distantly related M. xanthus strains segregated during both vegetative growth and development.
- The type VI secretion system (T6SS) mediated antagonism between strains.
- WT strain mixtures formed monoclonal fruiting bodies, while T6SS knockout mixtures formed chimeric fruiting bodies.
Conclusions:
- T6SS is the primary mechanism for kin discrimination in distantly related M. xanthus.
- T6SS ensures the development of monoclonal fruiting bodies, maintaining social integrity.
- This mechanism prevents exploitation by non-kin and stabilizes cooperative multicellular development.
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