Ontogeny of a symbiont-produced chemical defense in Bugula neritina (Bryozoa)

Lopanik, Nicole B.; Targett, Nancy M.; Lindquist, Niels

doi:10.3354/meps327183

Cited by 43 publications

(45 citation statements)

References 57 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The bryostatin signal persisted through the period of settlement and metamorphosis to the ancestrula, prior to formation of the protective chitinous shell. These results corroborate recent findings that although bryostatin concentrations are significantly lower in stages 4-h and 1-day postsettlement, this correlates with an increase in chitin and carbonate content (Lopanik et al, 2006). As the first zooid developed, the bryostatin signal diminished, corresponding potentially to the increase of surface protection due to the chitin shell.…”

Section: Discussionsupporting

confidence: 81%

Localization of ‘Candidatus Endobugula sertula’ and the bryostatins throughout the life cycle of the bryozoan Bugula neritina

2007

View full text Add to dashboard Cite

'Candidatus Endobugula sertula,' the uncultivated c-proteobacterial symbiont of the marine bryozoan Bugula neritina, synthesizes bryostatins, complex polyketides that render B. neritina larvae unpalatable to predators. Although the symbiosis is well described, little is known about the locations of 'E. sertula' or the bryostatins throughout larval settlement, metamorphosis and early development. In this study, we simultaneously localized 'E. sertula' and the bryostatins in multiple stages of the B. neritina life cycle, using a novel bryostatin detection method based on its known ability to bind mammalian protein kinase C. Our results suggest that the bryostatins are deposited onto the exterior of B. neritina larvae during embryonic development, persist on the larval surface throughout metamorphosis and are shed prior to cuticle formation. During metamorphosis, 'E. sertula' remains adhered to the larval pallial epithelium and is incorporated into the preancestrula cystid tissue layer, which ultimately develops into a bud and gives rise to the next zooid in the colony. Colocalization of bryostatin signal with aggregates of 'E. sertula' in buds of ancestrulae suggested new synthesis of bryostatins in ancestrulae. In adult B. neritina colonies, symbiont microcolonies were observed in the funicular cords of rhizoids, which likely result in asexual transmission of 'E. sertula' to regenerated colonies. Furthermore, bryostatin signal was detected on the surface of the rhizoids of adult B. neritina colonies. Through simultaneous localization of the bryostatins and the 'E. sertula,' we determined how 'E. sertula' is transmitted, and identified shifts in bryostatin localization throughout the life cycle of the host B. neritina.

show abstract

Section: Discussionsupporting

confidence: 81%

Localization of ‘Candidatus Endobugula sertula’ and the bryostatins throughout the life cycle of the bryozoan Bugula neritina

2007

View full text Add to dashboard Cite

show abstract

“…This increase was accompanied by a decrease in bryostatin levels. 257 Among adult colonies, brooding portions were found to be significantly unpalatable, while pinfish feeding was not reduced for the non-brooding portions. It was concluded that adults are protected by mechanisms unrelated to bryostatin defense, such as structural components.…”

Section: Bryostatinsmentioning

confidence: 97%

Biosynthesis of polyketides by trans-AT polyketide synthases

2010

View full text Add to dashboard Cite

show abstract

“…The bryostatins are a family of polyketides that are found in marine bryozoans and are believed to be produced by bacterial symbionts (6). These compounds have demonstrated feeding deterrence against relevant predatory fish and are believed to protect the juvenile free-swimming bryozoans until they settle and develop structural defenses (7).…”

mentioning

confidence: 99%

Evolution of polyketide synthases in bacteria

Ridley

Lee

Khosla

2008

Proc. Natl. Acad. Sci. U.S.A.

172

157

View full text Add to dashboard Cite

The emergence of resistant strains of human pathogens to current antibiotics, along with the demonstrated ability of polyketides as antimicrobial agents, provides strong motivation for understanding how polyketide antibiotics have evolved and diversified in nature. Insights into how bacterial polyketide synthases (PKSs) acquire new metabolic capabilities can guide future laboratory efforts in generating the next generation of polyketide antibiotics. Here, we examine phylogenetic and structural evidence to glean answers to two general questions regarding PKS evolution. How did the exceptionally diverse chemistry of present-day PKSs evolve? And what are the take-home messages for the biosynthetic engineer?biosynthesis ͉ metabolism ͉ engineering P olyketides are a large family of medicinally important natural products, which are formed through the condensation of acylthioester units such as malonyl-CoA and methylmalonyl-CoA to yield metabolites with diverse structures and biological activities. Broadly speaking, there are three separate types of polyketide synthases (PKSs) recognized in bacteria. Multimodular PKSs consist of one or more large multidomain polypeptides where the growing polyketide chain is sequentially passed from one active site to the next. Depending on the nature of their constituent catalytic domains, these megasynthases generate chemical variety and complexity in a stepwise fashion (reviewed in ref. 1). In contrast, iterative PKSs are comprised of a single set of catalysts that assemble a polyketide of controlled chain length through repetitive use of active sites (reviewed in ref.2). In both cases, the nascent polyketide product is frequently acted on by further tailoring enzymes to generate the antibiotic. A third type of PKS (called type III PKSs) is fundamentally different in that the growing polyketide chain is never directly attached to a protein (reviewed in ref.3). This article focuses on the evolution of only the first two PKS classes.Bacteria, in particular Actinomycetes and Cyanobacteria, are prolific sources of polyketides, many of which possess antibiotic activity. Erythromycin, tetracycline, and amphotericin B are three well known examples of antimicrobial warfare agents from this group of bacteria that have been found useful for treating human diseases. Polyketides have also been discovered that play other roles in the environment other than to defeat microbial competitors. One such polyketide, mycolactone, is a pathogenesis-enabling immunosuppressant produced by the bacterium Mycobacterium ulcerans. This human pathogen is the causative agent of Buruli ulcer, but M. ulcerans mycolactone-negative mutants are avirulent. Addition of mycolactone to the mycolactone-negative mutants (chemical complementation) restores virulence (4). Other polyketides have been discovered that support a symbiotic relationship. One such compound, rhizoxin, is produced by a Burkholderia sp. symbiont of the fungus Rhizopus sp. Without the symbiont, the fungus cannot make the polyketide that functions to inh...

show abstract

Ontogeny of a symbiont-produced chemical defense in Bugula neritina (Bryozoa)

Cited by 43 publications

References 57 publications

Localization of ‘Candidatus Endobugula sertula’ and the bryostatins throughout the life cycle of the bryozoan Bugula neritina

Localization of ‘Candidatus Endobugula sertula’ and the bryostatins throughout the life cycle of the bryozoan Bugula neritina

Biosynthesis of polyketides by trans-AT polyketide synthases

Evolution of polyketide synthases in bacteria

Contact Info

Product

Resources

About