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1.
平端深海偏顶蛤(Gigantidasplatifrons)是南海台西南冷泉区的典型优势物种,鳃丝上皮细胞内共生大量甲烷氧化菌,通过甲烷有氧氧化合成有机物为共生体系提供物质能量,是平端深海偏顶蛤赖以生存的重要能量来源器官,溶酶体在共生体系的营养互作和稳态维持中可能发挥重要作用,本研究使用电镜技术观测了常压培养过程中(0d,30d,90d)平端深海偏顶蛤共生体系中共生菌和溶酶体的动态变化,通过鳃上皮含菌细胞超显微结构的变化研究常压培养对深海共生体系的影响,并探讨溶酶体在宿主—共生菌营养传递和共生菌群稳态维持中的关键作用。研究发现,在原位状态样品中(0d)共生菌和溶酶体呈极化分布,细胞结构完整清晰;蓄养30d后,含菌细胞出现明显破碎,共生菌数量大幅降低,溶酶体数量、范围和消化程度大幅增加,对细胞顶端的甲烷氧化菌进行分解;而90d后,共生菌在溶酶体的作用下消失殆尽,鳃部有明显细胞脱落后留下的坑洞,细胞呈现空泡状,无法明确区分各种细胞组分。上述结果展示了长期常压蓄养过程中鳃上皮含菌细胞中溶酶体与甲烷氧化菌的动态变化,推测当共生菌丢失后溶酶体也同步降低活跃度,平端深海偏顶蛤在共生互作中通过溶酶体主导消化和调控共生菌。 相似文献
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3.
Gaku Tokuda Akinori Yamada Kazuma Nakano Nao O. Arita & Hideo Yamasaki 《Marine Ecology》2008,29(1):106-114
Deep‐sea hydrothermal vents are unique light‐independent ecosystems that are sustained by chemosynthetic bacteria. For many of the invertebrates inhabiting in such environments, bacteria play essential roles in both energy acquisition and detoxification of potentially toxic gases such as H2S. In this study, the bacterial flora present on the gills of Alvinocaris longirostris (Bresiliidae: Caridea), a shrimp inhabiting hydrothermal vents (1532 m depth) at the Hatoma Knoll of the Okinawa Trough, was investigated. Bacterial 16S rDNA fragments were successfully amplified from the gills and 70% of these fragments showed an identical pattern in the restriction fragment length polymorphism analysis. These fragments were assigned to the ribotype AL‐1. Phylogenetic analyses suggest that AL‐1 forms a monophyletic clade with Sulfurovum spp. (ε‐Proteobacteria). Fluorescence in situ hybridization for AL‐1 and electron microscopy showed the presence of short‐rod bacteria lining up on the cuticular layer of the surface of the gill filaments. These results suggest that bacterial association with gills also occurs in bresiliid shrimps. 相似文献
4.
In order to correlate the expression of detoxifying enzyme genes and Cd accumulation in black sea bream, we analyzed four tissues (brain, gills, liver, and muscle) from black sea breams that were exposed to four different concentrations of Cd (0, 2, 13, and 25 mg/L) for various durations (0, 24, 48, 72, and 96 h). The highest level of Cd was accumulated in the liver, followed by the gills, brain, and muscle. The accumulation of Cd was significantly correlated with the duration of exposure and the concentration in brain, gill, and liver tissue, but not in muscle tissue, and the rate of accumulation increased with Cd concentration. The expression of metallothionein II (MT II) mRNA exhibited a similar pattern as Cd accumulation, especially in that the expression of MT II mRNA decreased in muscle tissue with increases in exposure duration. In contrast, the expression of cytochrome P450 1A (CYP1A) mRNA was highest in the liver, followed by brain, muscle, and gill tissues, and in gills and muscle tissue of Cd-exposed fish, the expression of CYP1A mRNA fell below that of the control fish. Overall, the liver of black sea bream was the most sensitive to Cd exposure, and the expression of MT II mRNA was 200-fold greater than the control fish. These findings indicate that the detoxification mechanisms of black sea bream are influenced by both MT II and CYP1A and that the genes participate in the detoxification of different tissues. 相似文献
5.
Maintenance of the glutathione (GSH) pathway is critical in guarding against the toxic effects of a variety of pollutants. However, despite their importance as an initial line of defense against waterborne toxicants, little is known regarding the role of fish gills in GSH-mediated xenobiotic metabolism. In these studies, the role of channel catfish gills in the detoxification of 2,4,5,6-tetrachloroisophthalonitrile (chlorothalonil), an electrophilic fungicide, was examined. Chlorothalonil was metabolized in vitro by gill cytosolic and microsomal glutathione S-transferases (GSTs). Chlorothalonil metabolism by cytosolic fructions was reduced markedly when GSH was omitted from reaction mixtures. Microsomal metabolism of chlorothalonil did not occur in the absence of GSH and in the presence of an NADPH-regenerating system lacking GSH. Channel catfish exposed in vivo to chlorothalonil had increased gill GSH and cysteine concentrations after 72 h exposure, and increased gill gamma-glutamylcysteine synthetase (GCS) activity at 144 h of exposure. Our results show that the gills play an important role in the metabolism and detoxification of chlorothalonil in the channel catfish. Catfish can maintain elevated gill GSH concentrations in the presence of chlorothalonil by increasing gill cysteine concentrations. 相似文献
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鲈鱼的鳃寄生车轮虫病及扫描电镜观察 总被引：1，自引：0，他引：1
报道鲈鱼的鳃寄生车轮虫病及病理组织的扫描电镜观察。病原鉴定为 :直钩车轮虫、杜氏车轮虫、日本车轮虫、劳牧小车轮虫及简单两分虫 5种车轮虫科纤毛虫 ,其中数量上占优势的为直钩车轮虫。扫描电镜观察结果表明 ,鳃寄生车轮虫可对宿主的上皮组织产生明显的机械性损伤并造成鳃丝粘液分泌增多及炎症反应。文中就海水养殖鱼类及野生鱼类由车轮虫寄生造成的危害及防治途径做了探讨。 相似文献
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中国对虾鳃的超微结构研究 总被引：1，自引：0，他引：1
本文报道中国对虾Ｐｅｎａｅｕｓｃｈｉｎｅｎｓｉｓ鳃的超微结构，结果表明，虾鳃具有三级结构，鳃瓣小叶是鳃的基本呼吸单位，它由鳃膜、呼吸上皮细胞及微血腔组成。文中分别描述了它们的超微结构特征，可供对虾组织细胞病理学诊断作对照参考。 相似文献
8.
Cold seeps have recently been discovered in the Nile deep‐sea fan (Eastern Mediterranean), and data regarding associated fauna are still scarce. In this study, two bivalve species associated with carbonate crusts and reduced sediment are identified based on sequence analysis of their 18S and 28S rRNA‐encoding genes, and associated bacterial symbioses are investigated using 16S rRNA gene sequencing and microscopy‐based approaches. The specimens are closely related to Myrtea spinifera and Thyasira flexuosa, two species previously documented at various depths from other regions but not yet reported from the Eastern Mediterranean. Both species harbour abundant gammaproteobacterial endosymbionts in specialized gill epithelial cells. The Myrtea‐associated bacterium is closely related to lucinid symbionts from both deep‐sea and coastal species, whereas the Thyasira‐associated bacterium is closely related to the symbiont of a T. flexuosa from coastal waters off the U.K. An epsilonproteobacterial sequence has also been identified in Thyasira which could correspond to a helicoid‐shaped morphotype observed by electron microscopy, but this was not confirmed using fluorescent in situ hybridization. Virus‐like particles were observed within some symbionts in Thyasira, mostly in bacteriocytes localized close to the ciliated zone of the gill filament. Overall, results indicate that very close relatives of shallow species M. spinifera and T. flexuosa occur at cold seeps in the Eastern Mediterranean and harbour chemoautotrophic symbioses similar to those found in their coastal relatives. 相似文献
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水产品鲐鱼(Pneumatophorus japonicus)细菌多样性及优势微生物分析 总被引：2，自引：0，他引：2
为研究鲐鱼(Pneumatophorus japonicus)在不同冻藏时期的优势微生物,并且得到一个较全面的细菌群落组成结构,采用16SrDNA基因克隆文库及克隆子分析等方法,分别对冻藏1d、8d和20d条件下鲐鱼鳃体系中的细菌种群多样性、优势微生物及其中产组胺菌的变化进行分析。结果表明,不同时期鲐鱼鳃内的细菌多样性均较强;冻藏1天的鳃体系中不动杆菌属(Acinetobacter)占优势为总数的77.5%,产组胺细菌如泛菌属(Pantoea)和肠杆菌属(Enterobacter)较少;第8天优势细菌种群是梭杆菌属(Fusobacteria bacterium)和希瓦氏菌属(Shewanella),而产组胺菌如发光杆菌属(Photobacterium)和弧菌属(Vibrio)较前期数量有所增加;冻藏到第20天的优势种群为哈夫尼菌属(Hafnia)和沙雷菌属(Serratia),它们均是产组胺的菌群。鲐鱼中细菌多样性及其优势微生物的变化等全面信息可为了解鲐鱼水产品组胺发生的微生物机制及其控制方法提供重要依据。 相似文献
10.
翡翠贻贝鳃的组织形态学和超微结构观察 总被引：1，自引：0，他引：1
应用光镜和透射电镜观察翡翠贻贝鳃的组织形态学和超微结构．翡翠贻贝身体两侧各有一对鳃瓣,覆盖在内脏团之上,鳃瓣由众多鳃丝组成．与其它种类贻贝相似,翡翠贻贝鳃丝上皮可区分为前微绒毛柱状细胞、前侧纤毛柱状细胞、立方或扁平细胞和后微绒毛柱状细胞等4个不同区带．电镜水平下可观察到鳃丝上具微绒毛柱状细胞、具纤毛柱状细胞、立方或扁平细胞、间质细胞和粘液细胞等5种细胞类型．本文对鳃丝的组织形态学及各类细胞的超微结构与功能作了描述及讨论． 相似文献
11.
Dailianis S Domouhtsidou GP Raftopoulou E Kaloyianni M Dimitriadis VK 《Marine environmental research》2003,56(4):443-470
The neutral red lysosomal retention assay (NRR) of the haemocytes, and the acetylcholinesterase activity (AChE) in the haemolymph, the digestive gland, the gills and the mantle/gonad complex have been evaluated on mussels Mytilus galloprovincialis collected from Thermaikos and Strymonikos gulfs (northern Greece) in June and October 2001. The validity of performing the above core biomarkers is supported, firstly by their ability to respond to different pollution levels and, secondly, by the significant linear correlation among them. The evaluation of the micronuclei frequency (MN) has been performed in gill tissue and haemocytes of the same mussels and, according to the results, it needs more research in order its use as stress indices to be validated. In addition, the first results on cAMP levels in the gills, the mantle/gonad complex and the digestive gland, whose concentrations correlated to both, NRR and AChE introduce this signal transduction molecule as a new, promising biomarker. 相似文献
12.
Fluorescent dyes and inhibitor compounds are commonly used to detect activity of multixenobiotic resistance (MXR) efflux pumps in marine invertebrates. We here address the question whether compounds acting as specific inhibitors of certain mammalian transporters can be used in dye efflux assays to distinguish different transporter activities in gill tissue from a marine mussel. We quantified effects of PSC833, a specific inhibitor of mammalian P-gp (P-glycoprotein, ABCB1), and MK571, which blocks MRP (Multidrug resistance associated protein, ABCC) type transporters, on calcein-am efflux in gill tissue of Mytilus californianus. Calcein-am acts as a substrate of both P-gp and MRP. Effects of single compounds and mixtures were determined and combined effect models predicting independent action (IA) and concentration addition (CA) of the chemicals were applied. Effect values predicted by IA showed better correspondence with the experimentally obtained data. This indicates that the inhibitor compounds target different mechanisms of calcein-am efflux and points to P-gp and MRP activities in mussel gills. Our approach could be a simple way for identifying the efflux transporter types targeted by chemosensitizers, including environmentally relevant compounds, in native tissues from marine invertebrates. 相似文献
13.
在实验生态条件下研究了重金属离子(Cu2 、Pb2 、Hg2 、Cd2 )对日本鳃丝和肝胰脏显微结构(15d)的影响。观察结果表明:在2 mg/L Cu2 处理组,日本鳃叶不规则增厚,鳃腔相对扩大,其中血细胞明显增多;上皮层出现破坏:角质膜(CU)呈波状拱起,部分上皮细胞脱离角质膜形成大的空泡(VA);上皮细胞排列不规则,并与数目众多的血细胞充挤于血腔;肝胰脏中构成肝管的细胞发生严重崩解,只残留包被在外周的一层结缔组织的被膜。10mg/L Pb2 处理组鳃丝角质膜明显呈波状突起;肝管结构紊乱,开始出现大量空泡(VA)。0.1 mg/L Hg2 暴露下,鳃丝上皮层偶有溶解现象;肝胰脏肝细胞空泡化(VA)现象更为严重,细胞间界限不明显,肝细胞溶解,有些细胞核固缩;被膜中的结缔组织充血,出现血细胞浸润现象。1 mg/L Cd2 暴露下,鳃丝上皮层严重解体,只剩一层角质层,鳃腔相对扩大,部分区域有充血现象;肝胰脏出现细胞质溶解,细胞间界限不明显,血细胞浸润等现象。 相似文献
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Perrine Cruaud Carole Decker Karine Olu Sophie Arnaud‐Haond Claire Papot Jocelyn Le Baut Adrien Vigneron Alexis Khripounoff Nicolas Gayet Ccile Cathalot Jean‐Claude Caprais Patricia Pignet Anne Godfroy Marie‐Anne Cambon‐Bonavita 《Marine Ecology》2019,40(3)
This study provides an analysis of vesicomyid bivalve–symbiont community distribution across cold seep and hydrothermal vent areas in the Guaymas Basin (Gulf of California, Mexico). Using a combination of morphological and molecular approaches including fluorescent in situ hybridization (FISH), and electronic microscopy observations, vesicomyid clam species and their associated symbionts were characterized and results were analyzed in light of geochemical conditions and other on‐site observations. A greater diversity of vesicomyids was found at cold seep areas, where three different species were present (Phreagena soyoae [syn. kilmeri], Archivesica gigas, and Calyptogena pacifica). In contrast, A. gigas was the only species sampled across the hydrothermal vent area. The same haplotype of A. gigas was found in both hydrothermal vent and cold seep areas, highlighting possible contemporary exchanges among neighboring vents and seeps. In either ecosystem, molecular characterization of the symbionts confirmed the specificity between symbionts and hosts and supported the hypothesis of a predominantly vertical transmission. In addition, patterns of clams could reflect potential niche preferences for each species. The occurrence of numerous traces of vesicomyid movements on sediments in the sites colonized by A. gigas seemed to indicate that this species might have a better ability to move. Furthermore, variation in gill sulfur content could reveal a higher plasticity and sulfur storage capacity in A. gigas. Thus, the distribution of vesicomyid species across the chemosynthetic areas of the Guaymas Basin could be explained by differences in biological traits of the vesicomyid species that would allow A. gigas to more easily exploit transient and punctual sources of available sulfide than P. soyoae. 相似文献
15.
Kinetic and toxicological characteristics of acetylcholinesterase from the gills of oysters (Crassostrea rhizophorae) and other aquatic species 总被引：1，自引：0，他引：1
The aim of this work was to characterize the cholinesterases from gills of Crassostrea rhizophorae in order to use them as biomarkers. Gills were homogenized and then centrifuged (9,000 x g, 4 degrees C, 30 min). S9 and Triton X-100 S9 treated (TX S9) fractions were employed as enzyme source. Km(ap) and Vmax were estimated, using acetylthiocholine iodide as substrate. Inhibition assays were performed with iso-OMPA and eserine. The Km(ap) for S9 and TX S9 fractions were 0.05 and 0.06 mM, whereas the Vmax were 1.92 and 5.84 nmol/min/mg protein. respectively. No inhibition was detected when the samples were incubated with iso-OMPA, suggesting the presence of acetylcholinesterases (AChE) in oyster gill homogenates. Sensitivity to eserine inhibition of AChE in the gills of oysters is intermediate when compared with other aquatic species. 相似文献
16.
Thomas K. Sawyer Earl J. Lewis Mark E. Galasso John J. Ziskowski 《Marine environmental research》1984,14(1-4)
Rock crabs, Cancer irroratus, were examined grossly and microscopically to estimate the influence of molting activity, geographical source and seabottom sediments on gill color, carapace color and tissue pathology. Collections were made from deepwater stations (20–55 m) in the Hudson Shelf Valley near dredge- and sewage-sludge disposal sites in the New York Bight apex, and from nearshore waters near Boothbay Harbor, Maine. Extensive gill blackening was noted in up to 30 % of the crabs from the New York stations when all specimens were in the intermolt condition. Blackening was not noted in intermolt crabs collected in Maine. Carapace blackening was present in up to 79 % of the New York crabs but absent in those from Maine. Severe blackening was attributed to direct contact of Cancer irroratus with blackened, highly organic sediments in the Hudson Shelf Valley. Fouling microorganisms on gill epicuticle included bacteria, diatoms, stalked ciliates, amoebae, flagellates and copepods. Bacteria, diatoms, amoebae and flagellates were common on crab gills from both locations. Ciliates and copepods counted in histological sections were considerably fewer in crabs from the New York stations than in those from Maine. Melanized nodules (hemocyte clumps) were present in gill tissue in up to 58 % of the New York crabs and in up to 68 % of Maine crabs. Unidentified microsporidans were found in up to 55 % of the New York specimens and in less than 2 % of those from Maine. Histological data accumulated since 1975 are summarized to provide a list of endoparasites, polychaete worms and barnacles observed in Cancer irroratus from the northeastern United States. Gill blackening, but not parasitism or microbial fouling, proved to be the best indicator or monitoring the effects of ocean dumping on the health of a benthic crustacean species. 相似文献
17.
为了解DOM与AgNPs的相互作用及其对AgNPs毒性的影响,本文以菲律宾蛤仔为受试生物、以水环境广泛存在腐殖酸(Humic acid,HA)为代表性有机质。通过贝类体内抗氧化系统的生物标志物(过氧化氢酶(Catalase,CAT)、超氧化物歧化酶(Superoxide dismutase,SOD)、金属硫蛋白(Metallothionein,MT)和丙二醛(Malondialdehyde,MDA))的响应,研究了HA对AgNPs生物效应的影响。结果表明,HA显著增加了AgNPs的稳定性,抑制了AgNPs的聚集。AgNPs(20μg·L-1)暴露3 d后,蛤仔鳃组织中Ag的蓄积显著上升,并随着时间的延长不断升高。AgNPs暴露第3、7天,不同浓度的HA条件下,鳃组织中Ag的蓄积无显著差异,但显著地低于无HA存在的AgNPs暴露组。CAT活性和MDA含量仅在无HA存在的AgNPs暴露组出现显著升高,其余各组之间无显著差异。表征DNA损伤程度的Olive尾矩(OTM)和尾长(TL)在无HA存在的AgNPs暴露组中随时间的延长不断上升。HA显著降低了AgNPs的对鳃组织细胞的遗传毒性。结果表明,HA通过增加AgNPs在介质中的稳定性而显著地抑制了鳃组织对Ag的蓄积,从而减弱了AgNPs对鳃组织的氧化胁迫和遗传毒性。结果证明了有机质含量等环境理化条件对纳米毒性存在显著影响。 相似文献
18.
Tubeworms within the annelid family Siboglinidae rely on sulfur-oxidizing autotrophic bacterial symbionts for their nutrition, and are among the dominant metazoans occurring at deep-sea hydrocarbon seeps. Contrary to their relatives from hydrothermal vents, sulfide uptake for symbionts occurs within the anoxic subsurface sediment, in the posterior ‘root’ region of the animal. This study reports on an integrated microbiological and geochemical investigation of the cold seep tubeworm Escarpia southwardae collected at the Regab pockmark (Gulf of Guinea). Our aim was to further constrain the links between the animal and its symbiotic bacteria, and their environment. We show that E. southwardae harbors abundant sulfur-oxidizing bacterial symbionts in its trophosome. Symbionts are able to fix inorganic carbon using the Calvin-Benson cycle, as reported in most other Siboglinidae, but can also use the reverse Tricarboxilic Acid Cycle. Surprisingly, the observed bacteria appear to be more closely related to symbionts of Escarpia and Lamellibrachia species from very distant sites located in the Gulf of Mexico and eastern Pacific, than to symbionts of a siboglinid occurring at a nearby methane seep site, only a few hundred km away from Regab. Then, by combining scanning electron microscopy and trace element (Mn, Fe, Sr, Zr) analyses of E. southwardae tube, we also show that two distinct oxidation fronts occur along the tube. The first one, near the posterior end of the tube, corresponds to the interface between oxic bottom waters and the underlying anoxic sediment. In contrast, the second redox front is located in the most anterior part of the tube, and could result from active oxygen uptake by the plume of the tubeworm. We speculate that intense oxygen consumption in this region could create favorable conditions for sulfate reduction by specialized bacteria associated with the plume, possibly leading to an additional source of dissolved sulfide that would further enhance the productivity of bacterial symbionts. 相似文献
19.
A. Viarengo S. Palmero G. Zanicchi R. Capelli R. Vaissiere M. Orunesu 《Marine environmental research》1985,16(1):23-36
The data presented in this paper demonstrate that exposure of mussels to Cu (40 μg/liter) or Cd (200 μg/liter) for a period of 2 days is sufficient to induce Cu or Cd thioneins in the gills of the metal-exposed animals. The concentrations of Cu and Cd thioneins increase during the period of metal exposure (3–4 weeks), confirming the fact that metallothioneins play a fundamental role in the accumulation of these metals in the tissues examined (gills and digestive gland). Moreover, it has been demonstrated that when metal-loaded mussels are returned to the field for the recovery period, Cu is rapidly eliminated from the gill and digestive gland cells, showing a biological half-life of 9–10 days, whereas Cd is released much more slowly from the tissues, only about 50% of the total metal being lost after 4 months of detoxification. Interestingly enough, during the detoxification period the concentration of the metal bound to thioneins also follows the same pattern as the total metal present in the tissues, in fact the concentration of Cu thioneins decreases near the control level in about 24 days but, in contrast, the Cd-thionein concentration in the cytisol of the gill and digestive gland cells remaains high, decreasing only by about 40% at the end of the 4 month recovery period.The data presented also demonstrate that when Cd-loaded, detoxified mussels are exposed to Cu (100 μg/liter) for 6 h, the metal taken up by the gill cells is able to displace the Zn which is always present in the Cd-thionein fraction, but it does not, however, displace the Cd present. In this case also, period (20 days), whereas the Cd-thionein content decreases slightly. Such data seem to indicate that the metabolic characteristics of thioneins are closely related to the metal bound to them, particularly where the elimination rate of the metals from the cells is concerned. 相似文献
20.
Intertidal blue mussels, Mytilus edulis, experience hypoxia reoxygenation during tidal emersion and resubmersion cycles, and this is often suggested to represent a major stress for the animals, especially for their respiratory tissues, the gills. We exposed mussels to experimental short and prolonged anoxia and subsequent reoxygenation and analyzed the respiratory response in excised gill tissue and the effects of treatment on reactive oxygen species (mainly ROS: superoxide anion, O2·− and hydrogen peroxide, H2O2), formation using live imaging techniques and confocal microscopy. Our aim was to understand if this “natural stress” would indeed produce oxidative damage and whether antioxidant defenses are induced under anoxia, to prevent oxidative damage during reoxygenation. Exposure to declining pO2 in the respiration chamber caused an increase of gill metabolic rate between 21 and 10 kPa, a pO2 range in which whole animal respiration is reported to be oxyregulating. Exposure of the animals to severe anoxia caused an onset of anaerobiosis (succinate accumulation) and shifted high and low critical pc values (pc1: onset of oxyregulation in gills, pc2: switch from oxyregulation to oxyconformity) to higher pO2. Concentrations of both ROS decreased strongly during anoxic exposure of the mussels and increased upon reoxygenation. This ROS burst induced lipid peroxidation in the mantle, but neither were protein carbonyl levels increased (oxidative damage in the protein fraction), nor did the tissue glutathione concentration change in the gills. Further, analysis of apoptosis markers indicated no induction of cell death in the gills. To our knowledge, this is the first paper that directly measures ROS formation during anoxia reoxygenation in mussels. We conclude that hypoxia tolerant intertidal mussels do not suffer major oxidative stress in gill and mantle tissues under these experimental conditions. 相似文献