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Host differentially expressed genes during association with its defensive endosymbiont
Meril Mathew1, Nicole B Lopanik
1Department of Biology, Georgia State University, Atlanta, Georgia 30303.
The Biological Bulletin
|May 7, 2014
Summary
The marine bryozoan Bugula neritina and its symbiont "Candidatus Endobugula sertula" coordinate bryostatin production. Host gene expression changes suggest B. neritina regulates symbiont distribution for larval protection.
Area of Science:
- Marine biology
- Microbial ecology
- Chemical ecology
Background:
- Mutualism in marine invertebrates often involves close host-symbiont interactions.
- Bugula neritina harbors the uncultured endosymbiont "Candidatus Endobugula sertula" (Ca. E. sertula).
- The symbiont is the suspected source of bryostatins, which protect B. neritina larvae.
Purpose of the Study:
- To investigate the host genes involved in the B. neritina - Ca. E. sertula mutualism.
- To understand how bryostatin localization is coordinated within the host colony.
- To identify host mechanisms regulating symbiont distribution and metabolite production.
Main Methods:
- Differential gene expression analysis in B. neritina colonies with and without Ca. E. sertula.
- Comparison of gene expression in reproductive and non-reproductive zooids.
- Bioinformatic analysis to identify downregulated host genes.
Main Results:
- Genes for glycosyl hydrolases, actin, and Rho-GDP dissociation inhibitor were significantly downregulated in symbiont-cured B. neritina.
- Downregulation was most pronounced in non-reproductive zooids lacking the symbiont.
- This suggests host regulation of symbiont presence and bryostatin localization.
Conclusions:
- Host B. neritina may control Ca. E. sertula distribution through biofilm degradation and actin rearrangement.
- This host regulation influences bryostatin localization to reproductive zooids for larval defense.
- The study reveals a sophisticated interplay in a marine invertebrate mutualism.
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