Vibrio fischeri Flagellin A Is Essential for Normal Motility and for Symbiotic Competence during Initial Squid Light Organ Colonization
AUTOR(ES)
Millikan, Deborah S.
FONTE
American Society for Microbiology
RESUMO
The motile bacterium Vibrio fischeri is the specific bacterial symbiont of the Hawaiian squid Euprymna scolopes. Because motility is essential for initiating colonization, we have begun to identify stage-specific motility requirements by creating flagellar mutants that have symbiotic defects. V. fischeri has six flagellin genes that are uniquely arranged in two chromosomal loci, flaABCDE and flaF. With the exception of the flaA product, the predicted gene products are more similar to each other than to flagellins of other Vibrio species. Immunoblot analysis indicated that only five of the six predicted proteins were present in purified flagella, suggesting that one protein, FlaF, is unique with respect to either its regulation or its function. We created mutations in two genes, flaA and flaC. Compared to a flaC mutant, which has wild-type flagellation, a strain having a mutation in the flaA gene has fewer flagella per cell and exhibits a 60% decrease in its rate of migration in soft agar. During induction of light organ symbiosis, colonization by the flaA mutant is impaired, and this mutant is severely outcompeted when it is presented to the animal as a mixed inoculum with the wild-type strain. Furthermore, flaA mutant cells are preferentially expelled from the animal, suggesting either that FlaA plays a role in adhesion or that normal motility is an advantage for retention within the host. Taken together, these results show that the flagellum of V. fischeri is a complex structure consisting of multiple flagellin subunits, including FlaA, which is essential both for normal flagellation and for motility, as well as for effective symbiotic colonization.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=421587Documentos Relacionados
- FlrA, a σ54-Dependent Transcriptional Activator in Vibrio fischeri, Is Required for Motility and Symbiotic Light-Organ Colonization
- Detection and quantification of Vibrio fischeri autoinducer from symbiotic squid light organs.
- Effect of transposon-induced motility mutations on colonization of the host light organ by Vibrio fischeri.
- Depressed light emission by symbiotic Vibrio fischeri of the sepiolid squid Euprymna scolopes.
- Two-Component Sensor Required for Normal Symbiotic Colonization of Euprymna scolopes by Vibrio fischeri