| a new niche for vibrio logei, the predominant light organ symbiont of squids in the genus sepiola. | two genera of sepiolid squids--euprymna, found primarily in shallow, coastal waters of hawaii and the western pacific, and sepiola, the deeper-, colder-water-dwelling mediterranean and atlantic squids--are known to recruit luminous bacteria into light organ symbioses. the light organ symbiont of euprymna spp. is vibrio fischeri, but until now, the light organ symbionts of sepiola spp. have remained inadequately identified. we used a combination of molecular and physiological characteristics to r ... | 1998 | 9422593 |
| induction of a gradual, reversible morphogenesis of its host's epithelial brush border by vibrio fischeri. | bacteria exert a variety of influences on the morphology and physiology of animal cells whether they are pathogens or cooperative partners. the association between the luminous bacterium vibrio fischeri and the sepiolid squid euprymna scolopes provides an experimental model for the study of the influence of extracellular bacteria on the development of host epithelia. in this study, we analyzed bacterium-induced changes in the brush borders of the light organ crypt epithelia during the initial ho ... | 1998 | 9453641 |
| host-derived amino acids support the proliferation of symbiotic bacteria. | animals are typically colonized by diverse bacterial symbionts, many of which are commensal and, in numerous cases, even essential for their host's proper development and growth. in exchange, the host must supply a sufficient array and quantity of nutrients to support the proliferation and persistence of its microbial community. in this investigation, we have examined such a nutritional environment by determining the symbiotic competence of auxotrophic mutants of the bioluminescent bacterium vib ... | 1998 | 9465100 |
| late postembryonic development of the symbiotic light organ of euprymna scolopes (cephalopoda: sepiolidae). | the symbiotic light organ of the sepiolid squid euprymna scolopes undergoes significant anatomical, morphological, and biochemical changes during development. previously we described the embryonic organogenesis and early postembryonic development of the light organ. during embryogenesis, tissues are developed that will promote the onset of an association with vibrio fischeri, the light organ symbiont. upon inoculation, and in response to the first interactions with the bacterial symbionts, the l ... | 1998 | 9924775 |
| the muscle-derived lens of a squid bioluminescent organ is biochemically convergent with the ocular lens. evidence for recruitment of aldehyde dehydrogenase as a predominant structural protein. | many of the structural proteins of ocular lenses, commonly referred to as crystallins, are identical to specific enzymes or the result of a recent gene duplication (piatigorsky, j., and wistow, g. (1991) science 252, 1078-1079). one such enzyme, aldehyde dehydrogenase (aldh), has been recruited as a lens crystallin in certain mammals (wistow, g., and kim, h. (1991) j. mol. evol. 32, 262-269) and cephalopods (tomarev, s., zinovieva, r., and piatigorsky, j. (1991) j. biol. chem. 266, 24226-24231). ... | 1992 | 1400415 |
| vibrio fischeri lipopolysaccharide induces developmental apoptosis, but not complete morphogenesis, of the euprymna scolopes symbiotic light organ. | during initiation of the association between the squid host euprymna scolopes and its bacterial partner vibrio fischeri, the bacteria induce dramatic morphogenesis of the host symbiotic organ, a portion of which involves the signaling of widespread apoptosis of the cells in a superficial ciliated epithelium on the colonized organ. in this study, we investigated the role in this process of lipopolysaccharide (lps), a bacterial cell-surface molecule implicated in the induction of animal cell apopt ... | 2000 | 11023684 |
| a peroxidase related to the mammalian antimicrobial protein myeloperoxidase in the euprymna-vibrio mutualism. | many animal-bacteria cooperative associations occur in highly modified host organs that create a unique environment for housing and maintaining the symbionts. it has been assumed that these specialized organs develop through a program of symbiosis-specific or -enhanced gene expression in one or both partners, but a clear example of this process has been lacking. in this study, we provide evidence for the enhanced production of an enzyme in the symbiotic organ of the squid euprymna scolopes, whic ... | 1996 | 8942994 |
| construction and symbiotic competence of a luxa-deletion mutant of vibrio fischeri. | bioluminescence by the squid euprymna scolopes requires colonization of its light organ by the symbiotic luminous bacterium vibrio fischeri. investigation of the genetic determinants underlying bacterial symbiotic competence in this system has necessitated the continuing establishment and application of molecular genetic techniques in v. fischeri. we developed a procedure for the introduction of plasmid dna into v. fischeri by electroporation, and isolated a mutant strain that overcame the appar ... | 1996 | 8917081 |
| lessons from a cooperative, bacterial-animal association: the vibrio fischeri-euprymna scolopes light organ symbiosis. | although the study of microbe-host interactions has been traditionally dominated by an interest in pathogenic associations, there is an increasing awareness of the importance of cooperative symbiotic interactions in the biology of many bacteria and their animal and plant hosts. this review examines a model system for the study of such symbioses, the light organ association between the bobtail squid euprymna scolopes and the marine luminous bacterium vibrio fischeri. specifically, the initiation, ... | 1996 | 8905092 |
| growth and flagellation of vibrio fischeri during initiation of the sepiolid squid light organ symbiosis. | a pure culture of the luminous bacterium vibrio fischeri is maintained in the light-emitting organ of the sepiolid squid euprymna scolopes. when the juvenile squid emerges from its egg it is symbiont-free and, because bioluminescence is part of an anti-predatory behavior, therefore must obtain a bacterial inoculum from the surrounding environment. we document here the kinetics of the process by which newly hatched juvenile squids become infected by symbiosis-competent v. fischeri. when placed in ... | 1993 | 8439236 |
| abundant mrnas in the squid light organ encode proteins with a high similarity to mammalian peroxidases. | a library derived from mrna in the bacterial light organ of the squid, euprymna scolopes, contained an unexpectedly high proportion of cdnas that encode proteins with approximately 30% similarity to a family of mammalian peroxidases (po) including myelo-po, eosinophil po, and thyroid po (donor:hydrogen-peroxide oxidoreductase; ec 1.11.1.7). two nearly full-length cdnas were determined to encode putative po of nearly 93 kda each that are 97% identical in amino acid sequence to each other. each co ... | 1993 | 8224867 |
| effect of transposon-induced motility mutations on colonization of the host light organ by vibrio fischeri. | vibrio fischeri is found both as a free-living bacterium in seawater and as the specific, mutualistic light organ symbiont of several fish and squid species. to identify those characteristics of symbiosis-competent strains that are required for successful colonization of the nascent light organ of juvenile euprymna scolopes squids, we generated a mutant pool by using the transposon mu di 1681 and screened this pool for strains that were no longer motile. eighteen independently isolated nonmotile ... | 1994 | 7961462 |
| bacterial symbionts induce host organ morphogenesis during early postembryonic development of the squid euprymna scolopes. | the mutualistic association between the squid euprymna scolopes and the bacterium vibrio fischeri is an emerging experimental system for the study of the influence of bacteria on animal development. taking advantage of the ability to raise both this host and its microbial partner independently under laboratory conditions, we describe the effects of bacterial interactions on morphogenesis of the juvenile host symbiotic organ. our results show that bacteria are essential for normal postembryonic d ... | 1994 | 7924980 |
| detection and quantification of vibrio fischeri autoinducer from symbiotic squid light organs. | 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 core ... | 1995 | 7860584 |
| depressed light emission by symbiotic vibrio fischeri of the sepiolid squid euprymna scolopes. | bioluminescent marine bacteria of the species vibrio fischeri are the specific light organ symbionts of the sepiolid squid euprymna scolopes. although they share morphological and physiological characteristics with other strains of v. fischeri, when cultured away from the light organ association the e. scolopes symbionts depress their maximal luminescence over 1,000-fold. the primary cause of this reduced luminescence is the underproduction by these bacteria of luciferase autoinducer, a molecule ... | 1990 | 2163384 |
| symbiont recognition and subsequent morphogenesis as early events in an animal-bacterial mutualism. | bacterial colonization of the developing light organ of the squid euprymna scolopes is shown to be highly specific, with the establishment of a successful association resulting only when the juvenile host is exposed to seawater containing one of a subset of vibrio fischeri strains. before a symbiotic infection the organ has elaborate epithelial structures covered with cilia and microvilli that are involved in the transfer of bacteria to the incipient symbiotic tissue. these structures regressed ... | 1991 | 1962208 |
| physical and functional maps of the luminescence gene cluster in an autoinducer-deficient vibrio fischeri strain isolated from a squid light organ. | vibrio fischeri es114 is an isolate representing the specific bacterial light organ symbiont of the squid euprymna scolopes. an interesting feature of this strain of v. fischeri is that it is visibly luminous within the light organ of the squid host but is nonluminous when grown under standard laboratory conditions. luminescence can be restored in laboratory culture, however, by the addition of autoinducer, a species-specific inducer of the v. fischeri luminescence (lux) genes. most other isolat ... | 1992 | 1624432 |
| negotiations between animals and bacteria: the 'diplomacy' of the squid-vibrio symbiosis. | a shared characteristic among animals is their propensity to form stable, beneficial relationships with prokaryotes. usually these associations occur in the form of consortia, i.e. a diverse assemblage of bacteria interacting with a single animal host. these complex communities, while common, have been difficult to characterize. the two-partner symbiosis between the squid euprymna scolopes and the marine luminous bacterium vibrio fischeri offers the opportunity to study the interaction between a ... | 2000 | 10989339 |
| alterations in the proteome of the euprymna scolopes light organ in response to symbiotic vibrio fischeri. | during the onset of the cooperative association between the hawaiian sepiolid squid euprymna scolopes and the marine luminous bacterium vibrio fischeri, the anatomy and morphology of the host's symbiotic organ undergo dramatic changes that require interaction with the bacteria. this morphogenetic process involves an array of tissues, including those in direct contact with, as well as those remote from, the symbiotic bacteria. the bacteria induce the developmental program soon after colonization ... | 2000 | 10966433 |
| dominance of vibrio fischeri in secreted mucus outside the light organ of euprymna scolopes: the first site of symbiont specificity. | previous studies of the euprymna scolopes-vibrio fischeri symbiosis have demonstrated that, during colonization, the hatchling host secretes mucus in which gram-negative environmental bacteria amass in dense aggregations outside the sites of infection. in this study, experiments with green fluorescent protein-labeled symbiotic and nonsymbiotic species of gram-negative bacteria were used to characterize the behavior of cells in the aggregates. when hatchling animals were exposed to 10(3) to 10(6) ... | 2003 | 12839763 |
| establishment of an animal-bacterial association: recruiting symbiotic vibrios from the environment. | while most animal-bacterial symbioses are reestablished each successive generation, the mechanisms by which the host and its potential microbial partners ensure tissue colonization remain largely undescribed. we used the model association between the squid euprymna scolopes and vibrio fischeri to examine this process. this light organ symbiosis is initiated when v. fischeri cells present in the surrounding seawater enter pores on the surface of the nascent organ and colonize deep epithelia-lined ... | 2000 | 10963683 |
| the euprymna scolopes-vibrio fischeri symbiosis: a biomedical model for the study of bacterial colonization of animal tissue. | the diversity of microorganisms found in the marine environment reflects the immense size, range of physical conditions and energy sources, and evolutionary age of the sea. because associations with living animal tissue are an important and ancient part of the ecology of many microorganisms, it is not surprising that the study of marine symbioses (including both cooperative and pathogenic interactions) has produced numerous discoveries of biotechnological and biomedical significance. the associa ... | 1999 | 10941780 |
| novel effects of a transposon insertion in the vibrio fischeri glnd gene: defects in iron uptake and symbiotic persistence in addition to nitrogen utilization. | vibrio fischeri is the sole species colonizing the light-emitting organ of the hawaiian squid, euprymna scolopes. upon entering the nascent light organ of a newly hatched juvenile squid, the bacteria undergo morphological and physiological changes that include the loss of flagellation and the induction of bioluminescence. these and other events reveal a pattern of genetic regulation that is a response to the colonization of host tissue. in this study, we isolated and characterized a glnd:mtn5cm ... | 2000 | 10931314 |
| chemoattraction of vibrio fischeri to serine, nucleosides, and n-acetylneuraminic acid, a component of squid light-organ mucus. | newly hatched juveniles of the hawaiian squid euprymna scolopes rapidly become colonized by the bioluminescent marine bacterium vibrio fischeri. motility is required to establish the symbiotic colonization, but the role of chemotaxis is unknown. in this study we analyzed chemotaxis of v. fischeri to a number of potential attractants. the bacterium migrated toward serine and most sugars tested. v. fischeri also exhibited the unusual ability to migrate to nucleosides and nucleotides as well as to ... | 2003 | 14660408 |
| vibrio fischeri lux genes play an important role in colonization and development of the host light organ. | the bioluminescent bacterium vibrio fischeri and juveniles of the squid euprymna scolopes specifically recognize and respond to one another during the formation of a persistent colonization within the host's nascent light-emitting organ. the resulting fully developed light organ contains brightly luminescing bacteria and has undergone a bacterium-induced program of tissue differentiation, one component of which is a swelling of the epithelial cells that line the symbiont-containing crypts. while ... | 2000 | 10913092 |
| luxr- and acyl-homoserine-lactone-controlled non-lux genes define a quorum-sensing regulon in vibrio fischeri. | the luminescence (lux) operon (luxicdabeg) of the symbiotic bacterium vibrio fischeri is regulated by the transcriptional activator luxr and two acyl-homoserine lactone (acyl-hsl) autoinducers (the luxi-dependent 3-oxo-hexanoyl-hsl [3-oxo-c6-hsl] and the ains-dependent octanoyl-hsl [c8-hsl]) in a population density-responsive manner called quorum sensing. to identify quorum-sensing-regulated (qsr) proteins different from those encoded by lux genes, we examined the protein patterns of v. fischeri ... | 2000 | 10781550 |
| an exclusive contract: specificity in the vibrio fischeri-euprymna scolopes partnership. | | 2000 | 10714980 |
| aposymbiotic culture of the sepiolid squid euprymna scolopes: role of the symbiotic bacterium vibrio fischeri in host animal growth, development, and light organ morphogenesis. | the sepiolid squid euprymna scolopes forms a bioluminescent mutualism with the luminous bacterium vibrio fischeri, harboring v. fischeri cells in a complex ventral light organ and using the bacterial light in predator avoidance. to characterize the contribution of v. fischeri to the growth and development of e. scolopes and to define the long-term effects of bacterial colonization on light organ morphogenesis, we developed a mariculture system for the culture of e. scolopes from hatching to adul ... | 2000 | 10653967 |
| halide peroxidase in tissues that interact with bacteria in the host squid euprymna scolopes. | an enzyme with similarities to myeloperoxidase, the antimicrobial halide peroxidase in mammalian neutrophils, occurs abundantly in the light organ tissue of euprymna scolopes, a squid that maintains a beneficial association with the luminous bacterium vibrio fischeri. using three independent assays typically applied to the analysis of halide peroxidase enzymes, we directly compared the activity of the squid enzyme with that of human myeloperoxidase. one of these methods, the diethanolamine assay ... | 1999 | 10022605 |
| sampling the light-organ microenvironment of euprymna scolopes: description of a population of host cells in association with the bacterial symbiont vibrio fischeri. | the symbiosis between the squid euprymna scolopes and the luminous bacterium vibrio fischeri has a pronounced diel rhythm, one component of which is the venting of the contents of the light organ into the surrounding seawater each day at dawn. in this study, we explored the use of this behavior to sample the microenvironment of the light-organ crypts. intact crypt contents, which emerge from the lateral pores of the organ as a thick paste-like exudate, were collected from anesthetized host anima ... | 1998 | 9818359 |
| induction of apoptosis by cooperative bacteria in the morphogenesis of host epithelial tissues. | associations with pathogenic bacteria have recently been shown to initiate apoptotic programs in the cells of their animal hosts, where host cell death is hypothesized to be a response of the immune system, either initiated as a mechanism of host defense or bacterial offense. in this study, we present evidence that bacterial initiation of apoptosis is neither restricted to pathogenesis nor to the initation of an immune response. in the cooperative association between the sepiolid squid euprymna ... | 1998 | 9716720 |
| magnesium promotes flagellation of vibrio fischeri. | the bacterium vibrio fischeri requires bacterial motility to initiate colonization of the hawaiian squid euprymna scolopes. once colonized, however, the bacterial population becomes largely unflagellated. to understand environmental influences on v. fischeri motility, we investigated migration of this organism in tryptone-based soft agar media supplemented with different salts. we found that optimal migration required divalent cations and, in particular, mg2+. at concentrations naturally present ... | 2005 | 15743954 |
| vibrio fischeri genes hvna and hvnb encode secreted nad(+)-glycohydrolases. | hvna and hvnb are proteins secreted by vibrio fischeri es114, an extracellular light organ symbiont of the squid euprymna scolopes, that catalyze the transfer of adp-ribose from nad(+) to polyarginine. based on this activity, hvna and hvnb were presumptively designated mono-adp-ribosyltransferases (artases), and it was hypothesized that they mediate bacterium-host signaling. we have cloned hvna and hvnb from strain es114. hvna appears to be expressed as part of a four-gene operon, whereas hvnb i ... | 2001 | 11114931 |
| two-component sensor required for normal symbiotic colonization of euprymna scolopes by vibrio fischeri. | the light organ of the squid euprymna scolopes is specifically colonized to a high density by the marine bacterium vibrio fischeri. to date, only a few factors contributing to the specificity of this symbiosis have been identified. using a genetic screen for random transposon mutants defective in initiating the symbiotic association or in colonizing the light organ to high density, we identified a mutant of v. fischeri that exhibited an apparent defect in symbiosis initiation. this mutant was no ... | 2001 | 11208780 |
| anaerobic respiratory growth of vibrio harveyi, vibrio fischeri and photobacterium leiognathi with trimethylamine n-oxide, nitrate and fumarate: ecological implications. | two symbiotic species, photobacterium leiognathi and vibrio fischeri, and one non-symbiotic species, vibrio harveyi, of the vibrionaceae were tested for their ability to grow by anaerobic respiration on various electron acceptors, including trimethylamine n-oxide (tmao) and dimethylsulphoxide (dmso), compounds common in the marine environment. each species was able to grow anaerobically with tmao, nitrate or fumarate, but not with dmso, as an electron acceptor. cell growth under microaerophilic ... | 2000 | 11234928 |
| competition between vibrio fischeri strains during initiation and maintenance of a light organ symbiosis. | colonization of the light-emitting organ of the hawaiian squid euprymna scolopes is initiated when the nascent organ of a newly hatched squid becomes inoculated with vibrio fischeri cells present in the ambient seawater. although they are induced for luminescence in the light organ, these symbiotic strains are characteristically non-visibly luminous (nvl) when grown in laboratory culture. the more typical visibly luminous (vl) type of v. fischeri co-occurs in hawaiian seawater with these nvl str ... | 1994 | 8144466 |
| fundamental concepts in symbiotic interactions: light and dark, day and night, squid and legume. | the legume-rhizobium symbiosis and that between euprymna scolopes and vibrio fischeri show some surprising physiological similarities as well as differences. both interactions rely on exchange of signal molecules, some of which are derived from bacterial cell surface molecules. although the legume-rhizobium symbiosis is nutritionally based as are many animal-microbe symbioses, it is not obligate because the plant initiates nodule formation only when the soil is deficient in nitrogen. in contrast ... | 2000 | 11038222 |
| flra, a sigma54-dependent transcriptional activator in vibrio fischeri, is required for motility and symbiotic light-organ colonization. | flagellum-mediated motility of vibrio fischeri is an essential factor in the bacterium's ability to colonize its host, the hawaiian squid euprymna scolopes. to begin characterizing the nature of the flagellar regulon, we have cloned a gene, designated flra, from v. fischeri that encodes a putative sigma(54)-dependent transcriptional activator. genetic arrangement of the flra locus in v. fischeri is similar to motility master-regulator operons of vibrio cholerae and vibrio parahaemolyticus. in ad ... | 2003 | 12775692 |
| the vibrio fischeri quorum-sensing systems ain and lux sequentially induce luminescence gene expression and are important for persistence in the squid host. | bacterial quorum sensing using acyl-homoserine lactones (acyl-hsls) as cell-density dependent signalling molecules is important for the transcriptional regulation of many genes essential in the establishment and the maintenance of bacteria-host associations. vibrio fischeri, the symbiotic partner of the hawaiian bobtail squid euprymna scolopes, possesses two distinct acyl-hsl synthase proteins, luxi and ains. whereas the cell density-dependent regulation of luminescence by the luxi-produced sign ... | 2003 | 14507383 |
| population dynamics of vibrio fischeri during infection of euprymna scolopes. | the luminous bacterium vibrio fischeri colonizes a specialized light-emitting organ within its squid host, euprymna scolopes. newly hatched juvenile squid must acquire their symbiont from ambient seawater, where the bacteria are present at low concentrations. to understand the population dynamics of v. fischeri during colonization more fully, we used mini-tn7 transposons to mark bacteria with antibiotic resistance so that the growth of their progeny could be monitored. when grown in culture, the ... | 2003 | 14532046 |
| gaca regulates symbiotic colonization traits of vibrio fischeri and facilitates a beneficial association with an animal host. | the gacs/gaca two-component system regulates the expression of bacterial traits during host association. although the importance of gacs/gaca as a regulator of virulence is well established, its role in benign associations is not clear, as mutations in either the gacs or gaca gene have little impact on the success of colonization in nonpathogenic associations studied thus far. using as a model the symbiotic association of the bioluminescent marine bacterium vibrio fischeri with its animal host, ... | 2003 | 14645281 |
| vibrio fischeri sigma54 controls motility, biofilm formation, luminescence, and colonization. | in this study, we demonstrated that the putative vibrio fischeri rpon gene, which encodes sigma(54), controls flagellar biogenesis, biofilm development, and bioluminescence. we also show that rpon plays a requisite role initiating the symbiotic association of v. fischeri with juveniles of the squid euprymna scolopes. | 2004 | 15066853 |
| roles of bacterial regulators in the symbiosis between vibrio fischeri and euprymna scolopes. | | 2006 | 16623398 |
| correlation between osmolarity and luminescence of symbiotic vibrio fischeri strain es114. | vibrio fischeri isolates from euprymna scolopes are dim in culture but bright in the host. we found the luminescence of v. fischeri to be correlated with external osmolarity both in culture and in this symbiosis. luminescence enhancement by osmolarity was independent of the lux promoter and unaffected by autoinducers or the level of lux expression, but the addition of an aldehyde substrate for luciferase raised the luminescence of cells grown at high and low osmolarities to the same high level. ... | 2004 | 15090534 |
| vibrio fischeri luxs and ains: comparative study of two signal synthases. | vibrio fischeri possesses two acyl-homoserine lactone quorum-sensing systems, ain and lux, both of which are involved in the regulation of luminescence gene expression and are required for persistent colonization of the squid host, euprymna scolopes. we have previously demonstrated that the ain system induces luminescence at cell densities that precede lux system activation. our data suggested that the ain system both relieves repression and initially induces the lux system, thereby achieving se ... | 2004 | 15175301 |
| vibrio fischeri flagellin a is essential for normal motility and for symbiotic competence during initial squid light organ colonization. | 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 ... | 2004 | 15205434 |
| no means 'yes' in the squid-vibrio symbiosis: nitric oxide (no) during the initial stages of a beneficial association. | during colonization of the euprymna scolopes light organ, symbiotic vibrio fischeri cells aggregate in mucus secreted by a superficial ciliated host epithelium near the sites of eventual inoculation. once aggregated, symbiont cells migrate through ducts into epithelium-lined crypts, where they form a persistent association with the host. in this study, we provide evidence that nitric oxide synthase (nos) and its product nitric oxide (no) are active during the colonization of host tissues by v. f ... | 2004 | 15527494 |
| microbial factor-mediated development in a host-bacterial mutualism. | tracheal cytotoxin (tct), a fragment of the bacterial surface molecule peptidoglycan (pgn), is the factor responsible for the extensive tissue damage characteristic of whooping cough and gonorrhea infections. here, we report that vibrio fischeri also releases tct, which acts in synergy with lipopolysaccharide (lps) to trigger tissue development in its mutualistic symbiosis with the squid euprymna scolopes. as components of pgn and lps have commonly been linked with pathogenesis in animals, these ... | 2004 | 15539604 |
| the evolution of bioluminescent oxygen consumption as an ancient oxygen detoxification mechanism. | endogenous reductants such as hydrogen sulfide and alkylthiols provided free radical scavenging systems during the early evolution of life. the development of oxygenic photosynthesis spectacularly increased oxygen levels, and ancient life forms were obliged to develop additional antioxidative systems. we develop here the hypothesis of how "prototypical" bioluminescent reactions had a plausible role as an ancient defense against oxygen toxicity through their "futile" consumption of oxygen. as oxy ... | 2001 | 11343128 |
| vibrio fischeri outer membrane protein ompu plays a role in normal symbiotic colonization. | the nascent light-emitting organ of newly hatched juveniles of the hawaiian sepiolid squid euprymna scolopes is specifically colonized by cells of vibrio fischeri that are obtained from the ambient seawater. the mechanisms that promote this specific, cooperative colonization are likely to require a number of bacterial and host-derived factors and activities, only some of which have been described to date. a characteristic of many host-pathogen associations is the presence of bacterial mechanisms ... | 2001 | 11673429 |
| alterations in vibrio fischeri motility correlate with a delay in symbiosis initiation and are associated with additional symbiotic colonization defects. | motility is required for vibrio fischeri cells to interact with and specifically colonize the light-emitting organ of their host, the squid euprymna scolopes. to investigate the influence of motility on the expression of the symbiotic phenotype, we isolated mutants of the squid symbiont v. fischeri es114 that had altered migration abilities. spontaneous hyperswimmer (hs) mutants, which migrated more rapidly in soft agar and were hyperflagellated relative to the wild type, were isolated and group ... | 2002 | 11976129 |
| litr, a new transcriptional activator in vibrio fischeri, regulates luminescence and symbiotic light organ colonization. | vibrio fischeri is the bacterial symbiont within the light-emitting organ of the sepiolid squid euprymna scolopes. upon colonizing juvenile squids, bacterial symbionts grow on host-supplied nutrients, while providing a bioluminescence that the host uses during its nocturnal activities. mutant bacterial strains that are unable to emit light have been shown to be defective in normal colonization. a 606 bp open reading frame was cloned from v. fischeri that encoded a protein, which we named litr, t ... | 2002 | 12100554 |
| role for phosphoglucomutase in vibrio fischeri-euprymna scolopes symbiosis. | vibrio fischeri, a luminescent marine bacterium, specifically colonizes the light organ of its symbiotic partner, the hawaiian squid euprymna scolopes. in a screen for v. fischeri colonization mutants, we identified a strain that exhibited on average a 10-fold decrease in colonization levels relative to that achieved by wild-type v. fischeri. further characterization revealed that this defect did not result from reduced luminescence or motility, two processes required for normal colonization. we ... | 2002 | 12193629 |
| roles of vibrio fischeri and nonsymbiotic bacteria in the dynamics of mucus secretion during symbiont colonization of the euprymna scolopes light organ. | during light organ colonization of the squid euprymna scolopes by vibrio fischeri, host-derived mucus provides a surface upon which environmental v. fischeri forms a biofilm and aggregates prior to colonization. in this study we defined the temporal and spatial characteristics of this process. although permanent colonization is specific to certain strains of v. fischeri, confocal microscopy analyses revealed that light organ crypt spaces took up nonspecific bacteria and particles that were less ... | 2002 | 12324362 |
| the vibrio fischeri sapabcdf locus is required for normal growth, both in culture and in symbiosis. | inactivation of the sapabcdf genes results in a loss of virulence in several bacterial pathogens of animals and plants. the role of this locus in the growth physiology of vibrio fischeri, and in the symbiotic colonization of the squid euprymna scolopes was investigated. in rich medium, a v. fischeri sapa insertion mutant grew at only 85% the rate of its wild-type parent. while a similar effect has been attributed to a potassium-transport defect in sap mutants of enteric bacteria, the v. fischeri ... | 2002 | 12471505 |
| contribution of pila to competitive colonization of the squid euprymna scolopes by vibrio fischeri. | vibrio fischeri colonizes the squid euprymna scolopes in a mutualistic symbiosis. hatchling squid lack these bacterial symbionts, and v. fischeri strains must compete to occupy this privileged niche. we cloned a v. fischeri gene, designated pila, that contributes to colonization competitiveness and encodes a protein similar to type iv-a pilins. unlike its closest known relatives, vibrio cholerae msha and vcfa, pila is monocistronic and not clustered with genes associated with pilin export or ass ... | 2003 | 12571000 |
| the vibrio fischeri-euprymna scolopes light organ association: current ecological paradigms. | | 1998 | 16349524 |
| new rfp- and pes213-derived tools for analyzing symbiotic vibrio fischeri reveal patterns of infection and lux expression in situ. | genetically altered or tagged vibrio fischeri strains can be observed in association with their mutualistic host euprymna scolopes, providing powerful experimental approaches for studying this symbiosis. two limitations to such in situ analyses are the lack of suitably stable plasmids and the need for a fluorescent tag that can be used in tandem with green fluorescent protein (gfp). vectors previously used in v. fischeri contain the p15a replication origin; however, we found that this replicon i ... | 2006 | 16391121 |
| confocal microscopy of the light organ crypts in juvenile euprymna scolopes reveals their morphological complexity and dynamic function in symbiosis. | in the hours to days following hatching, the hawaiian bobtail squid, euprymna scolopes, obtains its light-emitting symbiont, vibrio fischeri, from the surrounding environment and propagates the bacteria in the epithelial crypts of a specialized light organ. three-dimensional analyses using confocal microscopy revealed that each of the three crypts on either side of the juvenile light organ is composed of four morphological regions. progressing from the lateral pore to the medial blind end of eac ... | 2006 | 16429442 |
| symbiotic role of the viable but nonculturable state of vibrio fischeri in hawaiian coastal seawater. | to achieve functional bioluminescence, the developing light organ of newly hatched juveniles of the hawaiian squid euprymna scolopes must become colonized by luminous, symbiosis-competent vibrio fischeri present in the ambient seawater. this benign infection occurs rapidly in animals placed in seawater from the host's natural habitat. therefore, it was surprising that colony hybridization studies with a v. fischeri-specific luxa gene probe indicated the presence of only about 2 cfu of v. fischer ... | 1995 | 16534910 |
| an annotated cdna library of juvenile euprymna scolopes with and without colonization by the symbiont vibrio fischeri. | biologists are becoming increasingly aware that the interaction of animals, including humans, with their coevolved bacterial partners is essential for health. this growing awareness has been a driving force for the development of models for the study of beneficial animal-bacterial interactions. in the squid-vibrio model, symbiotic vibrio fischeri induce dramatic developmental changes in the light organ of host euprymna scolopes over the first hours to days of their partnership. we report here th ... | 2006 | 16780587 |
| characterization and role of p53 family members in the symbiont-induced morphogenesis of the euprymna scolopes light organ. | within hours of hatching, the squid euprymna scolopes forms a specific light organ symbiosis with the marine luminous bacterium vibrio fischeri. interactions with the symbiont result in the loss of a complex ciliated epithelium dedicated to promoting colonization of host tissue, and some or all of this loss is due to widespread, symbiont-induced apoptosis. members of the p53 family, including p53, p63, and p73, are conserved across broad phyletic lines and p63 is thought to be the ancestral gene ... | 2006 | 16946237 |
| photolyase confers resistance to uv light but does not contribute to the symbiotic benefit of bioluminescence in vibrio fischeri es114. | recent reports suggest that the selective advantage of bioluminescence for bacteria is mediated by light-dependent stimulation of photolyase to repair dna lesions. despite evidence for this model, photolyase mutants have not been characterized in a naturally bioluminescent bacterium, nor has this hypothesis been tested in bioluminescent bacteria under natural conditions. we have now characterized the photolyase encoded by phr in the bioluminescent bacterium vibrio fischeri es114. consistent with ... | 2006 | 17021211 |
| vibrio fischeri and its host: it takes two to tango. | the association of vibrio fischeri and euprymna scolopes provides insights into traits essential for symbiosis, and the signals and pathways of bacteria-induced host development. recent studies have identified important bacterial colonization factors, including those involved in motility, bioluminescence and biofilm formation. surprising links between symbiosis and pathogenesis have been revealed through discoveries that nitric oxide is a component of the host defense, and that v. fischeri uses ... | 2006 | 17049299 |
| the gaca global regulator of vibrio fischeri is required for normal host tissue responses that limit subsequent bacterial colonization. | harmful and beneficial bacterium-host interactions induce similar host-tissue changes that lead to contrasting outcomes of association. a life-long association between vibrio fischeri and the light organ of its host euprymna scolopes begins when the squid collects bacteria from the surrounding seawater using mucus secreted from ciliated epithelial appendages. following colonization, the bacterium causes changes in host tissue including cessation of mucus shedding, and apoptosis and regression of ... | 2007 | 17081194 |
| complete genome sequence of vibrio fischeri: a symbiotic bacterium with pathogenic congeners. | vibrio fischeri belongs to the vibrionaceae, a large family of marine gamma-proteobacteria that includes several dozen species known to engage in a diversity of beneficial or pathogenic interactions with animal tissue. among the small number of pathogenic vibrio species that cause human diseases are vibrio cholerae, vibrio parahaemolyticus, and vibrio vulnificus, the only members of the vibrionaceae that have had their genome sequences reported. nonpathogenic members of the genus vibrio, includi ... | 2005 | 15703294 |
| vibrio fischeri uses two quorum-sensing systems for the regulation of early and late colonization factors. | vibrio fischeri possesses two quorum-sensing systems, ain and lux, using acyl homoserine lactones as signaling molecules. we have demonstrated previously that the ain system activates luminescence gene expression at lower cell densities than those required for lux system activation and that both systems are essential for persistent colonization of the squid host, euprymna scolopes. here, we asked whether the relative contributions of the two systems are also important at different colonization s ... | 2005 | 15901683 |
| a novel, conserved cluster of genes promotes symbiotic colonization and sigma-dependent biofilm formation by vibrio fischeri. | vibrio fischeri is the exclusive symbiont residing in the light organ of the squid euprymna scolopes. to understand the genetic requirements for this association, we searched a library of v. fischeri transposon insertion mutants for those that failed to colonize e. scolopes. we identified four mutants that exhibited severe defects in initiating colonization. sequence analysis revealed that the strains contained insertions in four different members of a cluster of 21 genes oriented in the same di ... | 2005 | 16102015 |
| characterization of pes213, a small mobilizable plasmid from vibrio fischeri. | most vibrio fischeri strains isolated from the euprymna scolopes light organ carry plasmids, often including both a large (>40kb) plasmid, and one or more small (<12kb) plasmids. the large plasmids share homology with pes100, which is the lone plasmid in v. fischeri type strain es114. pes100 appears to encode a conjugative system similar to that on plasmid r721. the small plasmids lack extensive similarity to pes100, but they almost always occur in cells that also harbor a large plasmid resembli ... | 2005 | 16122560 |
| the role of the immune system in the initiation and persistence of the euprymna scolopes--vibrio fischeri symbiosis. | the squid-vibrio symbiosis is an experimental system being studied as a model of the chronic colonization of animal epithelia by bacterial partners. one principal question being asked with this model is: what is the role of the immune system in the dynamics of the onset and maintenance of the symbiotic state? this review focuses upon results of research to date, which have demonstrated that both cell-mediated and cell-free components of the innate immune system are involved in these processes. | 2010 | 20036144 |
| identifying components of the nf-kappab pathway in the beneficial euprymna scolopes-vibrio fischeri light organ symbiosis. | the toll/nf-kappab pathway is a common, evolutionarily conserved innate immune pathway that modulates the responses of animal cells to microbe-associated molecular patterns (mamps). because mamps have been implicated as critical elements in the signaling of symbiont-induced development, an expressed sequence tag library from the juvenile light organ of euprymna scolopes was used to identify members of the toll/nf-kappab pathway. full-length transcripts were identified by using 5' and 3' race pcr ... | 2005 | 16269728 |
| detection of the light organ symbiont, vibrio fischeri, in hawaiian seawater by using lux gene probes. | symbiotic bacteria that inhabit the light-emitting organ of the hawaiian squid euprymna scolopes are distinctive from typical vibrio fischeri organisms in that they are not visibly luminous when grown in laboratory culture. therefore, the abundance of these bacteria in seawater samples cannot be estimated simply by identifying them among luminous colonies that arise on nutrient agar plates. instead, we have used luxr and polymerase chain reaction generated luxa gene probes to identify both lumin ... | 1992 | 16348678 |
| effect of the squid host on the abundance and distribution of symbiotic vibrio fischeri in nature. | euprymna scolopes, a hawaiian species of bioluminescent squid, harbors vibrio fischeri as its specific light organ symbiont. the population of symbionts grew inside the adult light organ with an average doubling time of about 5 h, which produced an excess of cells that were expelled into the surrounding seawater on a diurnal basis at the beginning of each period of daylight. these symbionts, when expelled into the ambient seawater, maintain or slightly increase their numbers for at least 24 h. h ... | 1994 | 16349257 |
| identification of a cellobiose utilization gene cluster with cryptic beta-galactosidase activity in vibrio fischeri. | cellobiose utilization is a variable trait that is often used to differentiate members of the family vibrionaceae. we investigated how vibrio fischeri es114 utilizes cellobiose and found a cluster of genes required for growth on this beta-1,4-linked glucose disaccharide. this cluster includes genes annotated as a phosphotransferase system ii (cela, celb, and celc), a glucokinase (celk), and a glucosidase (celg). directly downstream of celcbgka is celi, which encodes a laci family regulator that ... | 2008 | 18487409 |
| fnr-mediated regulation of bioluminescence and anaerobic respiration in the light-organ symbiont vibrio fischeri. | vibrio fischeri induces both anaerobic respiration and bioluminescence during symbiotic infection. in many bacteria, the oxygen-sensitive regulator fnr activates anaerobic respiration, and a preliminary study using the light-generating lux genes from v. fischeri mj1 cloned in escherichia coli suggested that fnr stimulates bioluminescence. to test for fnr-mediated regulation of bioluminescence and anaerobic respiration in v. fischeri, we generated fnr mutants of v. fischeri strains mj1 and es114. ... | 2010 | 20298504 |
| effects of luxcdabeg induction in vibrio fischeri: enhancement of symbiotic colonization and conditional attenuation of growth in culture. | production of bioluminescence theoretically represents a cost, energetic or otherwise, that could slow vibrio fischeri growth; however, bioluminescence is also thought to enable full symbiotic colonization of the euprymna scolopes light organ by v. fischeri. previous tests of these models have proven inconclusive, partly because they compared nonisogenic strains, or undefined and/or pleiotropic mutants. to test the influence of the bioluminescence-producing lux operon on growth and symbiotic com ... | 2008 | 18521572 |
| gene sequences of the pil operon reveal relationships between symbiotic strains of vibrio fischeri. | symbiosis between the bobtail squid euprymna scolopes (mollusca: cephalopoda) and vibrio fischeri bacteria has been a well-studied model for understanding the molecular mechanisms of colonization and adherence to host cells. for example, pilin expression has been observed to cause subtle variation in colonization for a number of gram-negative bacteria with eukaryotic hosts. to investigate variation amongst pil genes of closely related strains of vibrios, we amplified pil genes a, b, c and d to d ... | 2008 | 18523167 |
| genetic analysis of trimethylamine n-oxide reductases in the light organ symbiont vibrio fischeri es114. | trimethylamine n-oxide (tmao) reductases are widespread in bacteria and often function in anaerobic respiration. the regulation and expression of tmao reductase operons have been well studied in model genera such as escherichia, shewanella, and rhodobacter, although tmao reductases are present in many other bacteria, including the marine vibrio species. the genome sequence of vibrio fischeri revealed three putative tmao reductase operons, and a previous report identified tmao reductase activity ... | 2008 | 18606737 |
| effects of colonization, luminescence, and autoinducer on host transcription during development of the squid-vibrio association. | the light-organ symbiosis between the squid euprymna scolopes and the luminous bacterium vibrio fischeri offers the opportunity to decipher the hour-by-hour events that occur during the natural colonization of an animal's epithelial surface by its microbial partners. to determine the genetic basis of these events, a glass-slide microarray was used to characterize the light-organ transcriptome of juvenile squid in response to the initiation of symbiosis. patterns of gene expression were compared ... | 2008 | 18682555 |
| population structure of vibrio fischeri within the light organs of euprymna scolopes squid from two oahu (hawaii) populations. | we resolved the intraspecific diversity of vibrio fischeri, the bioluminescent symbiont of the hawaiian sepiolid squid euprymna scolopes, at two previously unexplored morphological and geographical scales. these scales ranged from submillimeter regions within the host light organ to the several kilometers encompassing two host populations around oahu. to facilitate this effort, we employed both novel and standard genetic and phenotypic assays of light-organ symbiont populations. a v. fischeri-sp ... | 2009 | 18997024 |
| attenuation of host no production by mamps potentiates development of the host in the squid-vibrio symbiosis. | bacterial pathogens typically upregulate the host's production of nitric oxide synthase (nos) and nitric oxide (no) as antimicrobial agents, a response that is often mediated by microbe-associated molecular patterns (mamps) of the pathogen. in contrast, previous studies of the beneficial euprymna scolopes/vibrio fischeri symbiosis demonstrated that symbiont colonization results in attenuation of host nos/no, which occurs in high levels in hatchling light organs. here, we sought to determine whet ... | 2011 | 21091598 |
| the symbiosis regulator rscs controls the syp gene locus, biofilm formation and symbiotic aggregation by vibrio fischeri. | successful colonization of a eukaryotic host by a microbe involves complex microbe-microbe and microbe-host interactions. previously, we identified in vibrio fischeri a putative sensor kinase, rscs, required for initiating symbiotic colonization of its squid host euprymna scolopes. here, we analysed the role of rscs by isolating an allele, rscs1, with increased activity. multicopy rscs1 activated transcription of genes within the recently identified symbiosis polysaccharide (syp) cluster. wild-t ... | 2006 | 17087775 |
| genome announcement: draft genome of phaeobacter gallaeciensis ang1; a dominant member of the accessory nidamental gland of euprymna scolopes. | phaeobacter gallaeciensis strain ang1 represents the dominant member of the bacterial consortium within the reproductive accessory nidamental gland (ang) of the squid euprymna scolopes. we present a 4.59mb assembly of its genome, which may provide clues as to how it benefits its host. | 2011 | 21551313 |
| responses of host hemocytes during the initiation of the squid-vibrio symbiosis. | within hours after colonization of the light organ of the squid euprymna scolopes by its bacterial symbiont vibrio fischeri, the symbiont triggers morphogenesis of the light organ. this process involves the induction of apoptosis in the cells of two superficial ciliated epithelial fields and the gradual regression of these surface structures over a 96-h period. in this study, microscopic examination of various squid tissues revealed that host hemocytes specifically migrate into the epithelial fi ... | 2007 | 17301329 |
| two-component response regulators of vibrio fischeri: identification, mutagenesis, and characterization. | two-component signal transduction systems are utilized by prokaryotic and eukaryotic cells to sense and respond to environmental stimuli, both to maintain homeostasis and to rapidly adapt to changing conditions. studies have begun to emerge that utilize a large-scale mutagenesis approach to analyzing these systems in prokaryotic organisms. due to the recent availability of its genome sequence, such a global approach is now possible for the marine bioluminescent bacterium vibrio fischeri, which e ... | 2007 | 17586650 |
| bioluminescence in vibrio fischeri is controlled by the redox-responsive regulator arca. | bioluminescence generated by the vibrio fischeri lux system consumes oxygen and reducing power, and it has been proposed that cells use this to counteract either oxidative stress or the accumulation of excess reductant. these models predict that lux expression should respond to redox conditions; yet no redox-responsive regulator of lux is known. we found that the luxicdabeg operon responsible for bioluminescence is repressed by the arcab system, which is activated under reducing conditions. cons ... | 2007 | 17590235 |
| characterization of htrb and msbb mutants of the light organ symbiont vibrio fischeri. | bacterial lipid a is an important mediator of bacterium-host interactions, and secondary acylations added by htrb and msbb can be critical for colonization and virulence in pathogenic infections. in contrast, vibrio fischeri lipid a stimulates normal developmental processes in this bacterium's mutualistic host, euprymna scolopes, although the importance of lipid a structure in this symbiosis is unknown. to further examine v. fischeri lipid a and its symbiotic function, we identified two paralogs ... | 2008 | 18065606 |
| the twin arginine translocation system contributes to symbiotic colonization of euprymna scolopes by vibrio fischeri. | in many bacteria, the twin arginine translocation (tat) system transports folded proteins across the cytoplasmic membrane, and these proteins can play a role in symbiotic or pathogenic infections. a role for the vibrio fischeri tat system was identified during symbiotic colonization of its host euprymna scolopes, demonstrating a function for the tat system in host colonization by a member of the vibrionaceae. using bioinformatics, mutant analyses, and green fluorescent protein fusions, a set of ... | 2008 | 18217861 |
| rscs functions upstream of sypg to control the syp locus and biofilm formation in vibrio fischeri. | two-component signal transduction systems, composed of sensor kinase (sk) and response regulator (rr) proteins, allow bacterial cells to adapt to changes such as environmental flux or the presence of a host. rscs is an sk required for vibrio fischeri to initiate a symbiotic partnership with the hawaiian squid euprymna scolopes, likely due to its role in controlling the symbiosis polysaccharide (syp) genes and thus biofilm formation. to determine which rr(s) functions downstream of rscs, we perfo ... | 2008 | 18441059 |
| the putative hybrid sensor kinase sypf coordinates biofilm formation in vibrio fischeri by acting upstream of two response regulators, sypg and vpsr. | colonization of the hawaiian squid euprymna scolopes by the marine bacterium vibrio fischeri requires the symbiosis polysaccharide (syp) gene cluster, which contributes to symbiotic initiation by promoting biofilm formation on the surface of the symbiotic organ. we previously described roles for the syp-encoded response regulator sypg and an unlinked gene encoding the sensor kinase rscs in controlling syp transcription and inducing syp-dependent cell-cell aggregation phenotypes. here, we report ... | 2008 | 18469094 |
| ains quorum sensing regulates the vibrio fischeri acetate switch. | the marine bacterium vibrio fischeri uses two acyl-homoserine lactone (acyl-hsl) quorum-sensing systems. the earlier signal, octanoyl-hsl, produced by ains, is required for normal colonization of the squid euprymna scolopes and, in culture, is necessary for a normal growth yield. in examining the latter requirement, we found that during growth in a glycerol/tryptone-based medium, wild-type v. fischeri cells initially excrete acetate but, in a metabolic shift termed the acetate switch, they subse ... | 2008 | 18487321 |
| characterizing the host and symbiont proteomes in the association between the bobtail squid, euprymna scolopes, and the bacterium, vibrio fischeri. | the beneficial symbiosis between the hawaiian bobtail squid, euprymna scolopes, and the bioluminescent bacterium, vibrio fischeri, provides a unique opportunity to study host/microbe interactions within a natural microenvironment. colonization of the squid light organ by v. fischeri begins a lifelong association with a regulated daily rhythm. each morning the host expels an exudate from the light organ consisting of 95% of the symbiont population in addition to host hemocytes and shed epithelial ... | 2011 | 21998678 |
| h-nox-mediated nitric oxide sensing modulates symbiotic colonization by vibrio fischeri. | the bioluminescent bacterium vibrio fischeri initiates a specific, persistent symbiosis in the light organ of the squid euprymna scolopes. during the early stages of colonization, v. fischeri is exposed to host-derived nitric oxide (no). although no can be both an antimicrobial component of innate immunity and a key signaling molecule in eukaryotes, potential roles in beneficial host-microbe associations have not been described. v. fischeri hnox encodes a heme no/oxygen-binding (h-nox) protein, ... | 2010 | 20404170 |
| an alternative route to nitric oxide resistance. | vibrio fischeri is a bioluminescent bacterium that enters into a symbiosis with the bobtail squid euprymna scolopes. the bacterium colonizes a specialized light organ, in which it generates light that might help the squid to hide its silhouette from animals beneath it. previous studies have shown that the host nitric oxide (no) synthase is active during colonization, suggesting that v. fischeri symbionts are exposed to no. thus, no might play a role in regulating the symbiosis, a role possibly a ... | 2010 | 20487269 |
| bright mutants of vibrio fischeri es114 reveal conditions and regulators that control bioluminescence and expression of the lux operon. | vibrio fischeri es114, an isolate from the euprymna scolopes light organ, produces little bioluminescence in culture but is ∼1,000-fold brighter when colonizing the host. cell-density-dependent regulation alone cannot explain this phenomenon, because cells within colonies on solid medium are much dimmer than symbiotic cells despite their similar cell densities. to better understand this low luminescence in culture, we screened ∼20,000 mini-tn5 mutants of es114 for increased luminescence and iden ... | 2010 | 20693328 |
| ecdysone receptor homologs from mollusks, leeches and a polychaete worm. | the genomes of the mollusk lottia gigantea, the leech helobdella robusta and the polychaete worm capitella teleta each have a gene encoding an ecdysone receptor homolog. publicly available genomic and est sequences also contain evidence for ecdysone receptors in the seahare aplysia californica, the bobtail squid euprymna scolopes and the medicinal leech hirudo medicinalis. three-dimensional models of the ligand binding domains of these predicted ecdysone receptor homologs suggest that each of th ... | 2010 | 20934425 |
| contract theory for the evolution of cooperation: the right incentives attract the right partners. | partner choice is a critical stage of many biological interactions, from mating to cooperation. when the quality of the potential partners is unknown, one way to choose is to rely on signaling: costly signals can reveal the quality of the sender and allow the receiver to choose. in some cases, however, signaling (or an active choice based on signals) is not possible, for example in the initiation of the symbiosis between the squid euprymna scolopes and the bioluminescent bacterium vibrio fischer ... | 2010 | 21035464 |
| host-microbe symbiosis: the squid-vibrio association--a naturally occurring, experimental model of animal/bacterial partnerships. | many, if not most, animals have specific symbiotic relationships with bacterial partners. recent studies suggest that vertebrates create alliances with highly complex consortia of hundreds to thousands of prokaryotic phylotypes. in contrast, invertebrates often have binary associations, i.e., relationships with a population of a single bacterial species. in this chapter, the association between the hawaiian sepiolid squid euprymna scolopes and the marine luminous bacterium vibrio fisheri is high ... | 2008 | 18841707 |
| the lipid a from vibrio fischeri lipopolysaccharide: a unique structure bearing a phosphoglycerol moiety. | vibrio fischeri, a bioluminescent marine bacterium, exists in an exclusive symbiotic relationship with the hawaiian bobtail squid, euprymna scolopes, whose light organ it colonizes. previously it has been shown that the lipopolysaccharide (lps) or free lipid a of v. fischeri can trigger morphological changes in the juvenile squid's light organ that occur upon colonization. to investigate the structural features that might be responsible for this phenomenon, the lipid a from v. fischeri es114 lps ... | 2011 | 21498521 |
| structural and functional features of a developmentally regulated lipopolysaccharide-binding protein. | mammalian lipopolysaccharide (lps) binding proteins (lbps) occur mainly in extracellular fluids and promote lps delivery to specific host cell receptors. the function of lbps has been studied principally in the context of host defense; the possible role of lbps in nonpathogenic host-microbe interactions has not been well characterized. using the euprymna scolopes-vibrio fischeri model, we analyzed the structure and function of an lbp family protein, e. scolopes lbp1 (eslbp1), and provide evidenc ... | 2015 | 26463160 |