JB
Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow Copyright Information
Right arrow Books from ASM Press
Right arrow MicrobeWorld
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Millikan, D. S.
Right arrow Articles by Ruby, E. G.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Millikan, D. S.
Right arrow Articles by Ruby, E. G.
Journal of Bacteriology, July 2004, p. 4315-4325, Vol. 186, No. 13
0021-9193/04/$08.00+0     DOI: 10.1128/JB.186.13.4315-4325.2004
Copyright © 2004, American Society for Microbiology. All Rights Reserved.

Vibrio fischeri Flagellin A Is Essential for Normal Motility and for Symbiotic Competence during Initial Squid Light Organ Colonization

Deborah S. Millikan and Edward G. Ruby*

Pacific Biomedical Research Center, University of Hawaii, Honolulu, Hawaii 96813

Received 5 January 2004/ Accepted 29 March 2004

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.

* Corresponding author. Mailing address: Pacific Biomedical Research Center, University of Hawai'i, 41 Ahui Street, Honolulu, HI 96813. Phone: (808) 539-7309. Fax: (808) 599-4817. E-mail: eruby{at}hawaii.edu.

Journal of Bacteriology, July 2004, p. 4315-4325, Vol. 186, No. 13
0021-9193/04/$08.00+0     DOI: 10.1128/JB.186.13.4315-4325.2004
Copyright © 2004, American Society for Microbiology. All Rights Reserved.



This article has been cited by other articles:



Home Help [Feedback] [For Subscribers] [Archive] [Search] [Contents]
Appl. Environ. Microbiol. Infect. Immun. Eukaryot. Cell
Mol. Cell. Biol. J. Virol. Microbiol. Mol. Biol. Rev.
ALL ASM JOURNALS

Copyright © 2004 by the American Society for Microbiology. All rights reserved.