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1.
1. Isolated photophores from the luminous fish Porichthys produce light in response to adrenaline and the metabolic inhibitors iodoacetic acid (IAA) or potassium cyanide (KCN).2. We attempted to analyse the interactions of cellular metabolism and adrenergic stimulation of the photogenic cells.3. Photophores were treated with IAA in the presence of pyruvate. In these conditions, IAA does inhibit glycolysis without inducing any luminescent activity of the cells.4. Similarly, other photophores were incubated with KCN in the presence of glucose, in order to inhibit cellular respiration while keeping the luminous system inactive.5. We observed that adrenergic stimulation of these photophores remained effective and induced a light emission, demonstrating that glycolytic and oxidative metabolism are not absolutely essential to the mechanism underlying adrenergic activation of the luminous system.6. The comparison of these luminescences with adrenergic responses of control photophores showed that the light emission to adrenaline was markedly inhibited by glycolysis blockade but potentiated by an inhibition of cellular respiration.7. As the inhibitory effect of IAA does not result from a direct action of IAA on the luminous system, these results suggest that adrenaline activation of adrenergic receptors might interact with glycolysis in photogenic cells.8. Glyceraldehyde 3-phosphate, or some derivatives, could be implicated in the glycolytic control of luminescence in the photophores.  相似文献   

2.
The development of luminous structures and the acquisition of luminescence competence during the ontogeny of the velvet belly lantern shark Etmopterus spinax, a deep‐sea squalid species, were investigated. The sequential appearance of nine different luminous zones during shark embryogenesis were established, and a new terminology for them given. These zones form the complex luminous pattern observed in free‐swimming animals. The organogenesis of photophores (photogenic organs) from the different luminous zones was followed, and photophore maturation was marked by the appearance of green fluorescent vesicles inside the photocytes (photogenic cells). Peroxide‐induced light emissions as well as spontaneous luminescence analysis indicated that the ability of E. spinax to produce light was linked to the presence of these fluorescent vesicles and occured prior to birth. The size of photogenic organs, as well as the percentage of ventral body surface area occupied by the luminous pattern and covered by photophores increased sharply during embryogenesis but remained relatively stable in free‐swimming animals. All these results strongly suggest camouflage by counter‐illumination in juvenile E. spinax.  相似文献   

3.
In most symbioses between animals and luminous bacteria it has been assumed that the bacterial symbionts luminesce continuously, and that the control of luminescent output by the animal is mediated through elaborate accessory structures, such as chromatophores and muscular shutters that surround the host light organ. However, we have found that while in the light organ of the sepiolid squid Euprymna scolopes, symbiotic cells of Vibrio fischeri do not produce a continuously uniform level of luminescence, but instead exhibit predictable cyclic fluctuations in the amount of light emitted per cell. This daily biological rhythm exhibits many features of a circadian pattern, and produces an elevated intensity of symbiont luminescence in juvenile animals during the hours preceding the onset of ambient darkness. Comparisons of the specific luminescence of bacteria in the intact light organ with that of newly released bacteria support the existence of a direct host regulation of the specific activity of symbiont luminescence that does not require the intervention of accessory tissues. A model encompassing the currently available evidence is proposed for the control of growth and luminescence activity in the E. scolopes/V. fischeri light organ symbiosis.Abbreviations CFU colony-forming-unit - LD light-dark  相似文献   

4.
Bioluminescence is known to be of great ecological importance to a luminous organism but extremely few studies investigate the ontogeny of luminous capabilities. The photogenic pattern of the velvet belly lantern shark Etmopterus spinax was investigated over ontogeny (14.0–52.5 cm total length) to determine the scaling of the surface area and the photophore density of different luminous zones as well as the ecological consequences of ontogenetic variations in bioluminescence efficiency. According to the luminous zone considered, different scaling patterns were found for the surface areas while the photophore densities of all zones scale with negative allometry, even though photophore insertion occurs. No sexual differences in these relationships were found. Luminous zones can be placed in two morphologically different groups: the “coverage” and the “isolated” zones. While counter-illumination is certainly the function of the former, the latter are probably involved in intraspecific behaviours. Due to the discrepancy between luminous capabilities of these two luminous zone categories, there is an ontogenetic increase in the luminescence heterogeneity of the luminous pattern as it was shown by luminescence modelling and confirmed by direct observations of spontaneous luminescence in living sharks. This heterogeneity certainly represents a trade-off between an efficient ventral camouflage and a strong identification tool for intraspecific behaviours such as coordinate hunting, which would be particularly useful when E. spinax become fish eaters (>19 cm total length), and for sexual recognition in mature individuals.  相似文献   

5.
The luminescent land snail Dyakia striata displayed a bioluminescence spectrum with a maximum wavelength of 515 nm. A green fluorescent substance extracted from the photogenic organ of an adult snail had a similar wavelength maximum but its fluorescence spectrum differed from that of flavin chromophore substances involved in light emission in some other luminescent organisms.  相似文献   

6.
The bioluminescence of the luminous mushroom, Lampteromyces japonicus, was studied by using the mushroom gills and also the luminous mycelia, the latter being cultured from the isolated spores and grown in a potato sucrose medium. The luminescence intensity of the mushroom gills and the cultured mycelia was measured in an aqueous suspension under various conditions. The original intensity was enhanced by exposing the luminous cells to oxygen for several hours or to acids or bases for a short period. This enhancement enabled measurement of their bioluminescence spectra which were identical to the fluorescence spectrum of riboflavin, having a maximum at 524 nm. The green fluorescent substance was extracted with cold water from the mushroom and it was identified as riboflavin by spectroscopic and chromatographic analyses. Riboflavin was concluded to be the light emitter of this mushroom.  相似文献   

7.
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 reveal that the light organs of Sepiola affinis and Sepiola robusta contain a mixed population of Vibrio logei and V. fischeri, with V. logei comprising between 63 and 100% of the bacteria in the light organs that we analyzed. V. logei had not previously been known to exist in such symbioses. In addition, this is the first report of two different species of luminous bacteria co-occurring within a single light organ. The luminescence of these symbiotic V. logei strains, as well as that of other isolates of V. logei tested, is reduced when they are grown at temperatures above 20°C, partly due to a limitation in the synthesis of aliphatic aldehyde, a substrate of the luminescence reaction. In contrast, the luminescence of the V. fischeri symbionts is optimal above 24°C and is not enhanced by aldehyde addition. Also, V. fischeri strains were markedly more successful than V. logei at colonizing the light organs of juvenile Euprymna scolopes, especially at 26°C. These findings have important implications for our understanding of the ecological dynamics and evolution of cooperative, and perhaps pathogenic, associations of Vibrio spp. with their animal hosts.  相似文献   

8.
The effect of aflatoxin B1 on growth and luminescence of marine luminous bacteria P. phosphoreum and recombinant E. coli Z905 cells was investigated. The bidirectional effect of aflatoxin B1 on the studied bacterial species was detected—an inhibition of luminescence in P. phosphoreum and its stimulation in E. coli. It was shown that aflatoxin B1 influences the cell luminescence in the freshly grown cultures and bacteria restored after lyophilization. It was detected that the effect of aflatoxin B1 was graded after interaction with the modified nanodiamond (MND) of detonation synthesis. After mycotoxin’s treatment with MND, it does not cause significant changes in bacterial luminescence. The possibilities for the use of P. phosphoreum and E. coli bacteria in the bioluminescent monitoring of aflatoxin B1 and the use of MND for mycotoxin deactivation are discussed.  相似文献   

9.
The DNA-damaging agents mitomycin C and UV irradiation, as well as the DNA-synthesis inhibitors nalidixic acid, novobiocin and coumermycin, induce the de novo synthesis of luciferase and in vivo luminescence in dark variant cells of the luminous bacteria Photobacterium leiognathi. Mitomycin C and nalidixic acid also cause the induction of luminescence in wild-type cells in the absence of its natural inducer. In spite of the high level of in vivo luminescence of the treated dark-variant cells, none of these agents result in the appearance of genetically luminous revertants. The possibility is discussed that these agents phenotypically induce luminescence through their ability to trigger ‘SOS functions’, which in turn leads to the transitory inactivation of certain repressors.  相似文献   

10.
A new method for the stimulation of bioluminescence in the dinoflagellate Gonyaulax polyedra is described. With this technique, in which cells flow through a capillary coil, it is possible to graduate the intensity of the stimulus by varying the flow rate. In continuous darkness, the threshold stimulus for cells in the middle of the day phase is greater than that for cells in the middle of the night phase. Some evidence suggests heterogeneity of sensitivity to stimulation among either cells or individual luminescent sources within a cell. At stimulus intensities much above threshold, the luminescence of both day- and night-phase cells is proportional to the number of cells within the capillary coil. Night-phase cells emit about 14 times as much light as do day-phase cells in continuous darkness.  相似文献   

11.
A previously unknown association between a luminous Vibrio sp., taxonomically related to the species Vibrio harveyi and a common member of the shallow/mid water communities of the Mediterranean Sea, the hydrozoan Clytia linearis is described. All the specimens of C. linearis observed under blue light excitation showed both a natural luminescence appearing as a series of fine dots due to clytin, and a clear fluorescence on the external side of the perisarc around the colonies due to the presence of luminous bacteria. Luminous bacteria were isolated from the surface of C. linearis, their phenotypic characterization as isolates was performed by several morphological, biochemical, and cultural tests, completed with 16S rDNA sequence analysis. All the isolates were referred to a Vibrio sp. taxonomically related to V. harveyi. The association of the V. harveyi-related species with C. linearis, as already suggested for another hydroid, Aglaophenia octodonta, could be explained with the activity of these bacteria of feeding on the chitinous structures present in these hydroids. Moreover, the adhesion of the luminous bacterium (here referred to as Vibrio sp. CL1) on C. linearis may contribute to the survival of this Vibrio species in the marine environment providing a suitable growth habitat.  相似文献   

12.
Kjeld  Hansen  Peter J.  Herring 《Journal of Zoology》1977,182(1):103-124
Females of the anglerfish genus Linophryne bear barbels containing luminous organs, in addition to an escal light organ. Luminescence has been observed from the barbels of four species of Linophryne , and the morphology of the luminous organs investigated. The barbel light organs do not contain bacteria but complex paracrystalline photogenic granules. The esca contains luminous bacteria. The esca is ectodermal in origin whereas the barbel organs may be derived from the mesoderm.
The possible significance of this unique dual system of luminous organs is discussed.  相似文献   

13.
Several strains of four species of luminous marine bacteria were maintained in a chemostat at a constant dilution rate and a variety of steady state densities by carbon (glycerol) limitation in order to study the relationship between culture density and bioluminescence activity. In general, luminescence per cell was constant at high culture density, and decreased dramatically at low culture density. For Vibrio fischeri, luminescence decreased to nondectable levels when the culture was maintained at low density; such dark cells were stimulated to synthesize luciferase and became luminous within minutes when purified autoinducer was added to the chemostat. Two strains, Photobacterium phosphoreum NZ11D and Photobacterium leiognathi S1, did not show the decrease in light intensity at low culture density that was characteristic of all other strains tested; they appeared to be constitutive for bioluminescence.Abbreviations BCM basal salts glycerol medium - BM basal salts medium - BSA bovine serum albumin - D dilution rate - DTT dilitiothreitol - LU light unit=2×1010 quanta s-1 - OD optical density - SWC sea water complete medium - specific growth rate  相似文献   

14.
Photosomes are the characteristic organelles of the luminous epithelium in the elytral appendages of polynoïd annelids. They are paracrystals of endoplasmic reticulum and emit a flash of bioluminescence in response to stimulation. The series of flashes in response to repetitive stimulation begins with a period of facilitation because the number of reacting photosomes increases in each photogenic cell. Reacting photosomes are coupled to the plasma membrane by dyad junctions which are established under stimulation and dedifferentiate in the resting system. The calcium influx of an action potential propagated through the conducting elytral epithelium triggers the luminous reaction. This reaction is based on a membrane photoprotein, polynoidin, which is specifically triggered by superoxide radicals. These oxy radicals result from the oxydation of riboflavin, which is present in a compartment of the photosomes. Polynoidin proved to be an interesting probe in the detection of superoxide radicals produced by activated white blood cells. Its potential applications are discussed.  相似文献   

15.
The Effect of Pre-irradiation on the Content of Growth Substances in Xi-Plants of Brassica oleracea var. acephala. The auxin content of growth stimulated young plants (Brassica oleraceav ar. acephala) of the X2-generation, originating from X-ray irradiated seeds (75 kR) was determined. Methanolic extracts were separated on thin-layer-chromatograms, which were analyzed by ultra-violet light and various chemical reactions. Quantitative determinations of growth substances were made using the Avena-coleoptile-cylinder-test. The following results were obtained: 1. X2-plants had a higher content of IAN compared with unirradiated control samples; 2. IAAm was detectable in only two out of 40 experiments; 3. Two fluorescent substances were detected: a hydroxycinnarmc acid derivative and a long chained unsatu-rated ketone or aldehyde, which is still unknown.  相似文献   

16.
1. Ca and K condition the irritability of Pelagia both in regard to rhythmical contractions and general luminescence. If either ion is omitted from the solution conduction of stimuli for pulsations and luminescence does not occur, although local responses still persist. 2. When Mg is omitted from the solution, Pelagia shows hyper-irritability with respect to rhythmical contraction and general luminescence. This is referable to the unantagonized action of K and Ca ions. 3. Exposure to the carbon arc suppresses general luminescence, the effect depending upon the quantity of light i.e. intensity x time of exposure. 4. The luminescent material secreted by Pelagia is inactive in sea water, but when put into salt solutions is activated by some of them. The efficiency of the salts, measured by brightness of light, is in the following order: MgSO4, K2SO4, Na3 citrate, KCl, BaCl2, SrCl2, CaCl2, and LiCl while NaCl and MgCl2 act as inhibitors. 5. Acidity inhibits the reaction, alkalinity promotes it. NH4OH in concentrations 0.27 N to 0.9 N causes luminescence for 10 minutes at 20°. 6. The average temperature coefficient for the reaction of the luminescent substance when activated by ammonia or MgSO4 is 2.18 for a temperature interval of 10°C. 7. The luminescence reaction cannot be the result of cytolysis, because (a) raising the temperature of sea water in which luminous material is immersed does not cause luminescence, although sufficient to produce cytolysis. (b) The salt solutions used in our experiments to cause luminescence, do not act cytolytically on cells in general.  相似文献   

17.
Among sixteen groups of luminous forms investigated by the author, in only four (fireflies, Pholas, ostracods, and Odontosyllis) is it possible to demonstrate the luciferin-luciferase reaction. In many groups this is probably due to the small amount of these substances present in the luminescent organism or to their instability. In the medusæ and pennatulids, despite a large amount of luminescent material, luciferin and luciferase cannot be demonstrated. This does not appear to be due to the presence of luciferin and luciferase in equivalent proportion, or to their instability. In fact, one is led to the conclusion that luciferin and luciferase do not exist in these forms, but such a conclusion must be regarded as merely tentative, in view of the fundamental character of the luciferin-luciferase reaction. Luciferin of one form will not luminesce with the luciferase of another form or vice versa, unless very closely related (Cypridina and Pyrocypris). All experiments emphasize the specificity of the light producing substances of Cypridina.  相似文献   

18.
Several species of the luminescent tubeshoulder fish (family Platytroctidae) show extensive ontogenetic transformations in the development of bioluminescent structures from larvae to adults. Several types of luminescent tissues are present in platytroctids, although these tissues are poorly known for most species because specimens are rarely observed. The present study describes the ontogenetic transformation of photogenic structures in Sagamichthys schnakenbecki, a species that is found in meso and bathy-pelagic depths of the Atlantic Ocean. Five newly described luminous structures are included in addition to a review of all known bioluminescent tissues described in the family. The newly discovered photogenic tissues were observed at the pectoral-fin base in early juveniles, as a pair of large globule-like tissues inside the caudal peduncle of early juveniles, at the pelvic girdle of late juveniles and early adults and as photogenic tissue observed as pigment over the cleithral bone in adults. A peculiar skin-slit structure, which was observed only in S. schnakenbecki, is described and discussed. Skin slits were associated with certain bioluminescent structures during the transformation into adulthood. In addition, coI sequence data from nine of 13 recognized platytroctid genera were used to construct the first molecular phylogenetic tree for the family. Finally, the first photographic evidence of the rarely observed luminous discharge of a tubeshoulder shoulder organ is presented from observations off south-east Greenland.  相似文献   

19.
Luminescence of the pony fish, Leiognathus elongatus, was observed in the natural environment during nighttime diving. The light was emitted from the lateroventral portion of the body, as bright rectangular-shaped luminescence patches turned on and off periodically. Luminescent fish had a distinct clear patch on the flank through which light was emitted, whereas non-luminous fish did not have such a clear patch. Both luminous and non-luminous fish were found within a shoal, where non-luminous individuals were chased by luminous ones. From previous morphological studies, the luminous and non-luminous individuals are likely to be male and female, respectively. Our observations provide field evidence that the luminescence functions as intraspecific communications in L. elongatus.  相似文献   

20.
Gaussia luciferase secreted by the copepod Gaussia princeps catalyzes the oxidation of coelenterazine to produce blue light. The primary structure of Gaussia luciferase deduced from the cDNA sequence shows two repeat sequences of 71 amino acid residues, suggesting the luciferase consists of two structural domains. Two domains in Gaussia luciferase were expressed independently in Escherichia coli cells, purified and characterized. We found that both domains have luminescence activity with coelenterazine, and the catalytic properties including luminescence spectrum, optimal pH, substrate specificity and luminescence stimulation by halogen ions (Cl, Br and I) are identical to intact Gaussia luciferase. Thus, Gaussia luciferase has two catalytic domains for the luminescence reaction.  相似文献   

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