Abstract
Vibrio fischeri is the specific light organ symbiont of the sepiolid squid species Euprymna scolopes and Euprymna morsei. Both species of squid are luminescent by virtue of their bacterial symbionts, but the natural symbionts of E. scolopes do not produce visible luminescence in laboratory culture. The primary cause of this depressed luminescence by E. scolopes symbionts in culture was found to be the production of relatively low levels of V. fischeri autoinducer, a positive transcriptional coregulator of the lux regulon, identified as N-(3-oxohexanoyl) homoserine lactone. Concentrations of autoinducer activity produced by these symbionts in culture were quantified and found to be at least 10-fold lower than those produced by E. morsei isolates (which are visibly luminous outside the association) and perhaps 10,000-fold lower than those of the brightest V. fischeri strains. Despite the differences in their symbiont strains, the intact light organs of the two species of squid contained comparable amounts of extractable autoinducer activity (between 100 and 200 pg per adult animal). The chromatographic behavior of this autoinducer activity on reverse-phase high-performance liquid chromatography was consistent with its presumptive identification as V. fischeri autoinducer. Within the 5-microliter volume of the epithelial core of the light organ in which the symbiotic V. fischeri strains are housed, these amounts would result in an effective autoinducer concentration of at least 100 nM. Because these levels are over 40-fold higher than the concentration needed for the induction of luminescence of bacteria in culture, we conclude that the inherent degree of autoinducer production by strains of V. fischeri may not influence their effectiveness as light organ symbionts. Furthermore, this study provides the first direct evidence that the phenomenon of cell density-dependent autoinduction, discovered and described first for laboratory cultures of V. fischeri but believed to be a general phenomenon in many species of host-associated symbionts and pathogens, is in fact a consequence of bacterial colonizations of host tissues.
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- Boettcher K. J., Ruby E. G. Depressed light emission by symbiotic Vibrio fischeri of the sepiolid squid Euprymna scolopes. J Bacteriol. 1990 Jul;172(7):3701–3706. doi: 10.1128/jb.172.7.3701-3706.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Cao J. G., Meighen E. A. Biosynthesis and stereochemistry of the autoinducer controlling luminescence in Vibrio harveyi. J Bacteriol. 1993 Jun;175(12):3856–3862. doi: 10.1128/jb.175.12.3856-3862.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Cao J. G., Meighen E. A. Purification and structural identification of an autoinducer for the luminescence system of Vibrio harveyi. J Biol Chem. 1989 Dec 25;264(36):21670–21676. [PubMed] [Google Scholar]
- Clarke H. R., Leigh J. A., Douglas C. J. Molecular signals in the interactions between plants and microbes. Cell. 1992 Oct 16;71(2):191–199. doi: 10.1016/0092-8674(92)90348-g. [DOI] [PubMed] [Google Scholar]
- Dolan K. M., Greenberg E. P. Evidence that GroEL, not sigma 32, is involved in transcriptional regulation of the Vibrio fischeri luminescence genes in Escherichia coli. J Bacteriol. 1992 Aug;174(15):5132–5135. doi: 10.1128/jb.174.15.5132-5135.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dunlap P. V., Greenberg E. P. Control of Vibrio fischeri luminescence gene expression in Escherichia coli by cyclic AMP and cyclic AMP receptor protein. J Bacteriol. 1985 Oct;164(1):45–50. doi: 10.1128/jb.164.1.45-50.1985. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dunlap P. V., Kuo A. Cell density-dependent modulation of the Vibrio fischeri luminescence system in the absence of autoinducer and LuxR protein. J Bacteriol. 1992 Apr;174(8):2440–2448. doi: 10.1128/jb.174.8.2440-2448.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Eberhard A., Burlingame A. L., Eberhard C., Kenyon G. L., Nealson K. H., Oppenheimer N. J. Structural identification of autoinducer of Photobacterium fischeri luciferase. Biochemistry. 1981 Apr 28;20(9):2444–2449. doi: 10.1021/bi00512a013. [DOI] [PubMed] [Google Scholar]
- Eberhard A. Inhibition and activation of bacterial luciferase synthesis. J Bacteriol. 1972 Mar;109(3):1101–1105. doi: 10.1128/jb.109.3.1101-1105.1972. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Engebrecht J., Nealson K., Silverman M. Bacterial bioluminescence: isolation and genetic analysis of functions from Vibrio fischeri. Cell. 1983 Mar;32(3):773–781. doi: 10.1016/0092-8674(83)90063-6. [DOI] [PubMed] [Google Scholar]
- Engebrecht J., Silverman M. Identification of genes and gene products necessary for bacterial bioluminescence. Proc Natl Acad Sci U S A. 1984 Jul;81(13):4154–4158. doi: 10.1073/pnas.81.13.4154. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Fuqua W. C., Winans S. C., Greenberg E. P. Quorum sensing in bacteria: the LuxR-LuxI family of cell density-responsive transcriptional regulators. J Bacteriol. 1994 Jan;176(2):269–275. doi: 10.1128/jb.176.2.269-275.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gray K. M., Greenberg E. P. Physical and functional maps of the luminescence gene cluster in an autoinducer-deficient Vibrio fischeri strain isolated from a squid light organ. J Bacteriol. 1992 Jul;174(13):4384–4390. doi: 10.1128/jb.174.13.4384-4390.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
- HASTINGS J. W., RILEY W. H., MASSA J. THE PURIFICATION PROPERTIES, AND CHEMILUMINESCENT QUANTUM YIELD OF BACTERIAL LUCIFERASE. J Biol Chem. 1965 Mar;240:1473–1481. [PubMed] [Google Scholar]
- Haygood M. G., Nealson K. H. Mechanisms of iron regulation of luminescence in Vibrio fischeri. J Bacteriol. 1985 Apr;162(1):209–216. doi: 10.1128/jb.162.1.209-216.1985. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kaplan H. B., Greenberg E. P. Diffusion of autoinducer is involved in regulation of the Vibrio fischeri luminescence system. J Bacteriol. 1985 Sep;163(3):1210–1214. doi: 10.1128/jb.163.3.1210-1214.1985. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lee K. H., Ruby E. G. Effect of the Squid Host on the Abundance and Distribution of Symbiotic Vibrio fischeri in Nature. Appl Environ Microbiol. 1994 May;60(5):1565–1571. doi: 10.1128/aem.60.5.1565-1571.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Meighen E. A., Dunlap P. V. Physiological, biochemical and genetic control of bacterial bioluminescence. Adv Microb Physiol. 1993;34:1–67. doi: 10.1016/s0065-2911(08)60027-2. [DOI] [PubMed] [Google Scholar]
- Meighen E. A. Molecular biology of bacterial bioluminescence. Microbiol Rev. 1991 Mar;55(1):123–142. doi: 10.1128/mr.55.1.123-142.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nealson K. H. Autoinduction of bacterial luciferase. Occurrence, mechanism and significance. Arch Microbiol. 1977 Feb 4;112(1):73–79. doi: 10.1007/BF00446657. [DOI] [PubMed] [Google Scholar]
- Nealson K. H., Hastings J. W. Bacterial bioluminescence: its control and ecological significance. Microbiol Rev. 1979 Dec;43(4):496–518. doi: 10.1128/mr.43.4.496-518.1979. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nealson K. H., Hastings J. W. Low oxygen is optimal for luciferase synthesis in some bacteria. Ecological implications. Arch Microbiol. 1977 Feb 4;112(1):9–16. doi: 10.1007/BF00446648. [DOI] [PubMed] [Google Scholar]
- Pearson J. P., Gray K. M., Passador L., Tucker K. D., Eberhard A., Iglewski B. H., Greenberg E. P. Structure of the autoinducer required for expression of Pseudomonas aeruginosa virulence genes. Proc Natl Acad Sci U S A. 1994 Jan 4;91(1):197–201. doi: 10.1073/pnas.91.1.197. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ruby E. G., Asato L. M. Growth and flagellation of Vibrio fischeri during initiation of the sepiolid squid light organ symbiosis. Arch Microbiol. 1993;159(2):160–167. doi: 10.1007/BF00250277. [DOI] [PubMed] [Google Scholar]
- Ruby E. G., McFall-Ngai M. J. A squid that glows in the night: development of an animal-bacterial mutualism. J Bacteriol. 1992 Aug;174(15):4865–4870. doi: 10.1128/jb.174.15.4865-4870.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ruby E. G., Nealson K. H. Symbiotic association of Photobacterium fischeri with the marine luminous fish Monocentris japonica; a model of symbiosis based on bacterial studies. Biol Bull. 1976 Dec;151(3):574–586. doi: 10.2307/1540507. [DOI] [PubMed] [Google Scholar]
- Stewart V., Parales J., Jr Identification and expression of genes narL and narX of the nar (nitrate reductase) locus in Escherichia coli K-12. J Bacteriol. 1988 Apr;170(4):1589–1597. doi: 10.1128/jb.170.4.1589-1597.1988. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Stock J. B., Rauch B., Roseman S. Periplasmic space in Salmonella typhimurium and Escherichia coli. J Biol Chem. 1977 Nov 10;252(21):7850–7861. [PubMed] [Google Scholar]