Symbiotic association of Photobacterium fischeri with the marine luminous fish Monocentris japonica; a model of symbiosis based on bacterial studies.

Isolation of bacteria from the luminous organ of the fish Monocentris japonica has revealed that the organ contains a pure culture of luminous bacteria. For the four fish examined, all contained Photobacterium fischeri as their luminous bacterial symbiont. This is the first time that P. fischeri has been identified in a symbiotic association. A representative isolate (MJl) of the light organ population was selected for in vivo studies of its luminous system. Several physiological features suggest adaptation for symbiotic existence. First, MJl has been shown to produce and respond to an inducer of luciferase that could accumulate in the light organ. Secondly, the specific activity of light production was seen to be maximal under low, growth-limiting concentrations of oxygen. Thirdly, unlike another luminous species (Beneckea harveyi), synthesis of the light production system of these bacteria is not catabolite repressed by glucose--a possible source of nutrition in the light organ. Fourthly, when grown aerobically on glucose these bacteria excrete pyruvic acid into the medium. This production of pyruvate is a major process, accounting for 30-40% of the glucose utilized and may serve as a form of regulatory and nutritional communication with the host.     

Luminous bacteria and light emitting fish: ultrastructure of the symbiosis

The luminescent fish Monocentris japonicus uses symbiotic luminous bacteria as a source of light. These bacteria live in light organs, complex tissue compartments, consisting of richly vascularized tubules or canals (in which the bacteria are cultured) lined with mitochondria-rich epithelial cells. The structure is consistent with a proposed model of symbiosis in which nutrients and oxygen are supplied by the vertebrate blood (vascular system). The nutrients, oxidized by the bacteria for growth and light production, are returned in part to the fish as pyruvate, which by reacting with mitochondrial oxygen regulates the light organ oxygen tensions. The luminous bacteria provide steady light that is modulated by passage through the melanocyte-containing dermis of the fish. Both the fish and the bacteria are highly adapted for their symbiotic coexistence.     

Genome sequence of Photobacterium mandapamensis strain svers.1.1, the bioluminescent symbiont of the cardinal fish Siphamia versicolor

Photobacterium mandapamensis is one of three luminous Photobacterium species able to form species-specific bioluminescent symbioses with marine fishes. Here, we present the draft genome sequence of P. mandapamensis strain svers.1.1, the bioluminescent symbiont of the cardinal fish Siphamia versicolor, the first genome of a symbiotic, luminous Photobacterium species to be sequenced. Analysis of the sequence provides insight into differences between P. mandapamensis and other luminous and symbiotic bacteria in genes involved in quorum-sensing regulation of light production and establishment of symbiosis.     

Delivery of germinal granules and localized RNAs via the messenger transport organizer pathway to the vegetal cortex of Xenopus oocytes occurs through directional expansion of the mitochondrial cloud

During Xenopus oogenesis, the message transport organizer (METRO) pathway delivers germinal granules and localized RNAs to the vegetal cortex of the oocyte via the mitochondrial cloud (Balbiani body). According to the traditional model, the mitochondrial cloud is thought to break up at the onset of vitellogenesis and the germinal granules and METRO-localized RNAs are transported within the mitochondrial cloud fragments to the vegetal cortex of the oocyte. We used light and electron microscopy in situ hybridization and three-dimensional reconstruction to show that germinal granules and METRO-localized RNAs are delivered to the oocyte cortex before the onset of mitochondrial cloud fragmentation and that the delivery involves accumulation of localized RNAs and aggregation of germinal granules at the vegetal tip of the mitochondrial cloud and subsequent internal expansion of the mitochondrial cloud between its animal (nuclear) and vegetal tips, which drives the germinal granules and METRO-localized RNAs toward the vegetal cortex. Thus the fragmentation of the cloud that occurs later in oogenesis is irrelevant to the movement of METRO-localized RNAs and germinal granules. On the basis of these findings, we propose here a revised model of germinal granule and localized RNAs delivery to the oocyte vegetal cortex via the METRO pathway.     

Contribution by symbiotically luminous fishes to the occurrence and bioluminescence of luminous bacteria in seawater

Seawater samples from a variety of locations contained viable luminous bacteria, but luminescence was not detectable although the system used to measure light was sensitive enough to measure light from a single, fully induced luminous bacterial cell. When the symbiotically luminous fishCleidopus gloriamaris was placed in a sterile aquarium, plate counts of water samples showed an increase in luminous colony-forming units. Luminescence also increased, decreasing when the fish was removed. Light measurements of water samples from a sterile aquarium containingPhotoblepharon palpebratus, another symbiotically luminous fish, whose bacterial symbionts have not been cultured, showed a similar pattern of increasing light which rapidly decreased upon removal of the fish. These experiments suggest that symbiotically luminous fishes release brightly luminous bacteria from light organs into their environment and may be a source of planktonic luminous bacteria. Although planktonic luminous bacteria are generally not bright when found in seawater, water samples from environments with populations of symbiotically luminous fish may show detectable levels of light.     

The Role of Superoxide Dismutase in Regulating the Light Emission of Luminescent Fungi

Luminescent fungi spontaneously emit light during certain stagesof their life cycles. Most of them are luminous during a partof their mycelial stage, but not many of them are luminous whenthey form fruiting bodies. In the case of Panellus stipticus,both the mycelium and the fruiting body can be luminous, andthe emission of light takes place when its luciferin is aerobicallyoxidized in the presence of the superoxide anion (O₂) and acationic surfactant. It is highly likely that the luminescencereactions of all kinds of luminous fungi are basically the sameas that of P. stipticus. In order to determine the factor thatmakes a fungus luminous or non-luminous, we studied the relationsbetween the light emission of fungi at various growth stagesand the contents of luciferin, its precursor, superoxide dismutase(SOD), and catalase, on six species of luminescent fungi: Armillariellamellea, Mycena citricolor, Mycena lux-coeli, Omphlotus olearious,Panellus stipticus, and Pleurotus japonicus. The analysis ofthe data suggested that the fungi generally contain the componentsnecessary for light emission, but also contain very large amountsof SOD which destroy O₂^–. If an appreciable amount ofSOD is distributed at the site of light emission, the luminescencereaction is prevented. For the reaction to take place, it isessential that the SOD activity at the site is sufficientlylow or inhibited, despite the high content of SOD in the wholetissue. Thus, the level of SOD activity at the site of lightemission appears to be a limiting factor in regulating the luminescenceof fungi. Key words: Bioluminescence, chemiluminescence, luminous fungi, superoxide ion, superoxide dismutase     

萤火虫(鞘翅目:萤科)两性交流中的闪光信号

对国内外萤火虫两性交流闪光信号的研究进行了综述,萤火虫发光器因种而异,多数发出黄绿色萤光,闪光信号的频率、光谱、强度及其时空分布的闪光模式包含着两性交流信息。萤火虫闪光交流系统有两种分类方法,其一是萤火虫具两个类型的闪光信号交流系统,及系统和系统,前者多在旧大陆,后者多在新大陆;其二是萤火虫具6个类型闪光信号交流系统,即HP,LL,LC,PR,CR和LB型,其中PR型与系统相对应,HP型与系统对应。萤火虫两性交流闪光信号常因时间和空间上的差异及外界物体的干扰使两性闪光交流的效率受到影响。萤火虫两性交流的闪光信号起源于鞘翅目的幼虫阶段,并起警戒天敌的作用,经过两性选择成为成虫两性交流的一种途径,进而成为新大陆的一些萤火虫间捕食猎物和逃避天敌的生存策略。     

Stimulation of luminescence of mycelium of luminous fungus Neonothopanus nambi by ionizing radiation

The luminescent system of higher luminous fungi is not fully understood and the enzyme/substrate pair of the light emission reaction has not been isolated. It was suggested that luminescence of fungi involves oxidase‐type enzymes, and reactive oxygen species are important for fungal light production. Generation of reactive oxygen species can be stimulated by ionizing irradiation, which has not been studied for luminous fungi. We report the effect of X‐irradiation on the luminescence of fungus Neonothopanus nambi. Experiments were performed with mycelium on a home‐built setup based on an X‐ray tube and monochromator/photomultiplier tube. Application of X‐rays does not change the emission spectrum, but after approximately 20 min of continuous irradiation, light production from unsupported mycelium starts growing and increases up to approximately five times. After peaking, its level decreases irrespective of the presence of X‐irradiation. After staying at a certain level, light production collapses to zero, which is not related to the drying of the mycelium or thermal impact of radiation. The observed shape of kinetics is characteristic of a multistage and/or chain reaction. The time profile of light production must reflect the current levels of radicals present in the system and/or the activity of enzyme complexes involved in light production. Copyright © 2014 John Wiley & Sons, Ltd.     

THE PENETRATION OF LUMINOUS BACTERIA BY THE AMMONIUM SALTS OF THE LOWER FATTY ACIDS : PART I. GENERAL OUTLINE OF THE PROBLEM,AND THE EFFECTS OF STRONG ACIDS AND ALKALIES.

It is shown that disappearance of the light of luminous bacteria may be used as a criterion of cell penetration; that luminous bacteria are cytolyzed by water, hypotonic solutions, and by freely penetrating solutions; that luminous bacteria are not injured by hydrogen or hydroxyl ions in the external solutions within the range of pH values employed with the ammonium salts and that therefore disappearance of the light in isotonic solutions of these salts must be due to penetration of the solute; and that there is a characteristic difference between the effects of strong and of weak acids and alkalies on luminous bacteria.     

Enlightenment of old ideas from new investigations: more questions regarding the evolution of bacteriogenic light organs in squids

Bioluminescence is widespread among many different types of marine organisms. Metazoans contain two types of luminescence production, bacteriogenic (symbiotic with bacteria) or autogenic, via the production of a luminous secretion or the intrinsic properties of luminous cells. Several species in two families of squids, the Loliginidae and the Sepiolidae (Mollusca: Cephalopoda) harbor bacteriogenic light organs that are found central in the mantle cavity. These light organs are exceptional in function, that is, the morphology and the complexity suggests that the organ has evolved to enhance and direct light emission from bacteria that are harbored inside. Although light organs are widespread among taxa within the Sepiolidae, the origin and development of this important feature is not well studied. We compared light organ morphology from several closely related taxa within the Sepiolidae and combined molecular phylogenetic data using four loci (nuclear ribosomal 28S rRNA and the mitochondrial cytochrome c oxidase subunit I and 12S and 16S rRNA) to determine whether this character was an ancestral trait repeatedly lost among both families or whether it evolved independently as an adaptation to the pelagic and benthic lifestyles. By comparing other closely related extant taxa that do not contain symbiotic light organs, we hypothesized that the ancestral state of sepiolid light organs most likely evolved from part of a separate accessory gland open to the environment that allowed colonization of bacteria to occur and further specialize in the eventual development of the modern light organ.     

STUDIES ON BIOLUMINESCENCE : XVII. FLUORESCENCE AND INHIBITION OF LUMINESCENCE IN CTENOPHORES BY ULTRA-VIOLET LIGHT.

1. Small dumps of the luminous cells of Mnemiopsis cannot readily be stimulated mechanically but will luminesce on treatment with saponin solution. Larger groups of luminous cells (such as are connected with two paddle plates) luminesce on mechanical stimulation. This suggests that mechanical stimulation to luminesce occurs chiefly through a nerve mechanism which has been broken up in the small dumps of luminous tissue. 2. The smallest bits of luminous tissue, even cells freed from the animal by agitation, that will pass through filter paper, lose their power to luminesce in daylight and regain it (at least partially) in the dark. 3. Luminescence of the whole animal and of individual cells is suppressed by near ultra-violet light (without visible light). 4. Inhibition in ultra-violet light is not due to stimulation (by the ultra-violet light) of the animal to luminesce, thereby using up the store of photogenic material. 5. Animals stimulated mechanically several times and placed in ultra-violet light show a luminescence along the meridians in the same positions as the luminescence that appears on stimulation. This luminescence in the ultra-violet or "tonic luminescence," is not obtained with light adapted ctenophores and is interpreted to be a fluorescence of the product of oxidation of the photogenic material. 6. Marked fluorescence of the luminous organ of the glowworm (Photuris) and of the luminous slime of Chatopterus may be observed in ultra-violet but no marked fluorescence of the luminous substances of Cypridina is apparent. 7. Evidence is accumulating to show a close relation between fluorescent and chemiluminescent substances in animals, similar to that described for unsaturated silicon compounds and the Grignard reagents.     

Factors increasing ethylene production enhance the sensitivity of root growth to auxins

Light inhibits root elongation, increases ethylene production and enhances the inhibitory action of auxins on root elongation of pea ( Pisum sativum L. cv. Weibulls Marma) seedlings. To investigate the role of ethylene in the interaction between light and auxin, the level of ethylene production in darkness was increased to the level produced in light by supplying 1-aminocyclopropane-1-carboxylic acid (ACC) or benzylaminopurine (BAP). Ethylene production was measured in excised root tips after treatment of intact seedlings for 24 h, while root growth was measured after 48 h. Auxin, at a concentration causing a partial inhibition of root elongation, did not increase ethylene production significantly. A 4-fold increase in ethylene production, caused either by light, 0.1 μ M ACC or 0.1 μ M BAP, inhibited root elongation by 40–50%. The auxins 2,4-dichlorophenoxyacetic acid and indolebutyric acid applied at 0.1 μ M inhibited root elongation by 15–25% in darkness but by 50–60% in light. Supply of ACC or BAP in darkness enhanced the inhibitory effects of auxins to about the same extent as in light. The inhibition caused by the auxins as well as by the BAP was associated with swelling of the root tips. ACC and BAP treatment synergistically increased the swelling caused by auxins. We conclude that auxin and ethylene, when applied or produced in partially inhibitory concentrations, act synergistically to inhibit root elongation and increase root diameter. The effect of light on the response of the roots to auxins is mediated by a light-induced increase in ethylene production.     

Evidence of luminous bacterial symbionts in the light organs of myctophid and stomiiform fishes

The myctophids and stomiiforms represent two common groups of luminous fishes, but the source of luminescence in these animals has remained undetermined. In this study, labeled luciferase gene fragments from luminous marine bacteria were used to probe DNA isolated from specific fish tissues. A positive signal was obtained from skin DNA in all luminous fishes examined, whereas muscle DNA gave a weaker signal and brain DNA was negative. This observation is consistent with luminous bacteria acting as the light source in myctophids and stomiiforms and argues against the genes necessary for luminescence residing on the fish chromosomes. To confirm the location of this signal, a bacterial probe was hybridized in situ to sections of a stomiiform. A strong signal was generated directly over specific regions of the fish light organs, whereas no signal was found over other internal or epidermal tissues of the fish. Taken together, these data provide the first indication that luminous bacterial symbionts exist in myctophids and stomiiforms and that these symbionts account for luminescence in these fishes.     

Dual bioluminescent systems in the anglerfish genus Linophryne (Pisces: Ceratioidea)

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.     

The fine structure of the light organ of the New Zealand glow-worm Arachnocampa luminosa (Diptera: Mycetophilidae).

The swollen distal tips of the Malpighian tubules of the glow-worm Arachnocampa luminosa constitute the light organ. The ventral and lateral surfaces are covered by a tracheal ‘reflector’ and the nervous supply to the light organ comes from the ganglion in the penultimate segment. Fine nerve terminals, axons, and glial cells can be seen in close proximity to the basal surface of the cells of the light organ. The epithelial cells of the light organ are large, the cytoplasm dense, homogeneous and acidophilic. The cytoplasm gives a strong positive reaction for protein. The cytoplasm contains a high density of free ribosomes, patches of dense material, smooth endoplasmic reticulum, glycogen and scattered microtubules. Mitochondria are numerous; they are large, randomly distributed and packed with fine cristae. These cells lack the features characteristic of Malpighian tubule epithelial cells; infolding of the apical and basal cell surfaces is reduced and the cytoplasm contains few organelles. These cells do not contain secretory or photocyte granules and the grainy cell matrix is thought to be the luciferin substrate. Oxygen is supplied via the tracheal layer (which may have secondary reflecting properties) and light production controlled by neurosecretory excitation either directly via synapses, or by hormones. There are no other reports of Malpighian tubules of insects producing light and the fine structure of these cells is distinct. Thus, the swollen distal tips of the Malpighian tubules of the glow-worm undoubtedly constitute a unique luminescent organ.     

Ethylene as a possible mediator of light-induced inhibition of root growth

Eliasson, L. and Bollmark, M. 1988. Ethylene as a possible mediator of light-induced inhibition of root growth. - Physiol. Plant. 72: 605–609.
Pea seedlings ( Pisum sativum L. cv. Weibull's Marma) were used to investigate the possible role of ethylene in light-induced inhibition of root elongation. Illumination of the roots with white light inhibited root elongation by 40–50% and increased ethylene production by the roots about 4-fold. Our main approach was to use exogenous 1-aminocyclopropane-1-carboxylic acid (ACC), supplied in the growth solution, to monitor ethylene production of the roots independent of light treatment. Ethylene production of excised root tips increased with increasing ACC concentrations. The rate of ethylene production in dark-grown roots treated with 0.1 μ M ACC was similar to that caused by illumination. Low ACC concentrations (0.01–0.1 μ M ) decreased the rate of root elongation, especially in seedlings grown in the dark, and 0.1 μ M ACC inhibited elongation to about the same extent as light. In light the roots curved and grew partly plagiogravitropically. This effect was also simulated by the 0.1 μ M ACC treatment. At 1 μ M and higher concentrations, ACC inhibited root growth almost completely and caused conspicuous curvatures of the root tips both in light and darkness. Inhibitors of ethylene synthesis and action partially counteracted the inhibition of root elongation caused by light. These observations suggest that the increase in ethylene production caused by light is at least partly responsible for the decreased growth of light-exposed roots.     

Bioluminescent organs of two deep-sea arrow worms, Eukrohnia fowleri and Caecosagitta macrocephala, with further observations on Bioluminescence in chaetognaths

Bioluminescence in the deep-sea chaetognath Eukrohnia fowleri is reported for the first time, and behavioral, morphological, and chemical characteristics of bioluminescence in chaetognaths are examined. Until this study, the only known species of bioluminescent chaetognath was Caecosagitta macrocephala. The luminescent organ of that species is located on the ventral edge of each anterior lateral fin, whereas that of E. fowleri runs across the center of the tail fin on both dorsal and ventral sides. Scanning electron microscopy showed that the bioluminescent organs of both species consist of hexagonal chambers containing elongate ovoid particles-the organelles holding bioluminescent materials. No other luminous organism is known to use hexagonal packing to hold bioluminescent materials. Transmission electron microscopy of particles from C. macrocephala revealed a densely packed paracrystalline matrix punctuated by globular inclusions, which likely correspond to luciferin and luciferase, respectively. Both species use unique luciferases in conjunction with coelenterazine for light emission. Luciferase of C. macrocephala becomes inactive after 30 min, but luciferase of E. fowleri is highly stable. Although C. macrocephala has about 90 times fewer particles than E. fowleri, it has a similar bioluminescent capacity (total particle volume) due to its larger particle size. In situ observations of C. macrocephala from a remotely operated vehicle revealed that the luminous particles are released to form a cloud. The discovery of bioluminescence in a second chaetognath phylogenetically distant from the first highlights the importance of bioluminescence among deep-sea organisms.     

发光甲虫与生物荧光

生物荧光是活体生物自身可以发光的有趣生命现象。具有这一现象的生物存在于生物四界中,但目前关于这一现象的研究报道主要来自于昆虫,尤其是以萤火虫为代表的发光甲虫的研究。文章对发光甲虫的分类地位、生物荧光发生的原理、发光器官的类型、闪光的“开关”机制、生物荧光的生物学意义及其相关行为学研究进展等进行了详细介绍。此外,还简要提及了荧光生物及其荧光酶的应用。这对了解及探讨生物荧光现象、加强对中国的发光甲虫及其它发光生物的研究及保护利用具有一定的借鉴作用。     

Field Evidence for Bioluminescent Signaling in the Pony Fish, Leiognathus elongatus

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.