共查询到20条相似文献，搜索用时 45 毫秒
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Craft JA Brown M Dempsey K Francey J Kirby MF Scott AP Katsiadaki I Robinson CD Davies IM Bradac P Moffat CF 《Marine environmental research》2004,58(2-5):419-423
Plaice, flounder and sand goby were exposed to ethynylestradiol (EE2) for 21 days and then followed for up to 31 days after removal of the oestrogen. Plasma vitellogenin (VTG) and hepatic VTG mRNA were determined in groups of fish sampled during the induction and post-exposure phases. VTG mRNA increased slightly earlier than plasma protein, but both reached maxima by 21 days. In contrast, VTG mRNA decayed much more rapidly than protein after EE2 exposure was terminated (typical values t(1/2) mRNA 3 days, protein 15-30 days). Vitellogenin and VTG mRNA thus measure different temporal events and this is illustrated by field data of male flounder in which both parameters have been determined. Few fish show co-ordinate increased VTG mRNA and vitellogenin but rather more fish have increased vitellogenin. Low level increases of VTG mRNA (5 X) is observed in some fish without increased vitellogenin and this may represent polymorphic differences between individual fish. 相似文献
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Scott AP Sanders M Stentiford GD Reese RA Katsiadaki I 《Marine environmental research》2007,64(2):128-148
Dab (Limanda limanda) caught in UK offshore waters show evidence of being exposed to estrogenic endocrine disrupters at a relatively low level. Two of 449 males caught between June and July 2005 had markedly elevated levels of vitellogenin (VTG; 21 and 750 microg/ml) and the remainder ranged from <0.01 to 8.6 microg/ml. Omitting the two outliers, there was a very significant positive relationship with the mass of individual males (a feature noted in previous studies on cod). Mean VTG concentrations in males differed significantly between sites. The site with the highest mean (1.6 microg/ml) was North East of the Dogger Bank and the site with the lowest (0.04 microg/ml) was in Cardigan Bay. Mean VTG concentrations in all North Sea fish were significantly higher than English Channel and Irish Sea fish, but this difference disappeared when fish mass was taken into account. VTG concentrations showed no relationship to water depth, stage of sexual maturity or age of the males. Sixty selected male plasmas were assayed for 17beta-estradiol but only two had measurable amounts (assay limit 0.04 ng/ml). Despite being the start of summer, the gonads of many of the males and females (especially those caught in the North Sea) showed signs of sexual maturity (presence of sperm in males and vitellogenic eggs in females). Many females had high VTG concentrations (up to 14 mg/ml) and 78 out of 80 had measurable concentrations of 17beta-estradiol. The cause of elevated VTG levels in male dab is unknown. As seen in cod, the presence of affected males does not appear to be linked to proximity to land or to known point sources of endocrine disrupters. However, our data, showing that larger fish are more likely to have elevated VTG concentrations, suggests a gradual accumulation by marine fish, probably through feeding, of persistent (probably relatively weak) estrogenic compounds. 相似文献
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饵料胆碱含量对真鲷仔稚鱼生长影响的初步研究 总被引：5，自引：0，他引：5
采用胆碱强化活饵料的方法研究活饵料量中胆碱含量对真鲷仔稚鱼生长和成活率的影响。说明胆碱是仔稚鱼生长，存活所必需的营养要素。 相似文献
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海水仔稚鱼营养的研究,国外已有相当数量的报道,特别是脂类中n-3高度不饱和脂肪酸(n-3HUFA)的研究,已取得显著的成果(Izquierdo et al.,1989a; Izquierdo et al.,1989b; Watanabe et al.,1994)。但迄今为止,我国鱼类营养的研究基本集中于幼鱼和成鱼阶段,仔稚鱼阶段还未见报道。目前,我国养殖的名贵海鱼,如真鯛(Pagrosomus major)、黑鯛(Sparus macrocephalus)、牙鲆(Paralichthys olivaceus)等的生产性育苗,因在仔稚鱼阶段大量死亡,成活率一般低于30%,某些营养要素的缺乏或不足是导致仔稚鱼大量死亡的一个重要原因。为加快我国海鱼养殖的发展,保证生产所需的优质种苗的供给,开展仔稚鱼营养的研究已成为我国鱼类营养研究工作者的一项极为紧迫的任务。
近年来,国外研究证实n-3HUFA是海水仔稚鱼的必需脂肪酸,其中以二十二碳六烯酸(DHA)和二十碳五烯酸(EPA)最为重要(Watanabe et al.,1989a; Watanabe et al.,1989b)。由于轮虫、卤虫等活饵料中DHA和EPA的含量很低,远不能满足海水仔稚鱼的需要,因而,有关学者通过选用优质单胞藻、制作油脂酵母、投喂富含n-3HUFA的人工微型佴料等方法强化活饵料。Watanabe等(1983)最早将富含n-3HUFA的鱼肝油等制成乳化油，直接加人培养活饵料的海水介质中,当富集于活饵料体内的n-3HUFA达到最大值时,将活饵料作为活的营养载体投喂给仔稚鱼,即可将外源n-3HUFA转移至仔稚鱼体内。该方法简便、实用,现已被推广(Izquierdo et al.,1989b)。
本研究采用乳化油直接添加法,人工调节卤虫体内n-3HUFA含量,探讨n-3HUFA对黑鲷稚鱼生长、存活的影响。 相似文献
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采用同源克隆和末端快速扩增(RACE)方法, 克隆了半滑舌鳎中 GnRHR 全长 cDNA。通过基因全长以及推断的氨基酸序列分析, 得知该序列包含一个 7tm-1 保守结构域, 为 G 蛋白偶联受体家族成员。利用 PHYLIP 3.5c 邻位相连法以及 DNAstar 中的 CLUSTAL W 方法对相应的氨基酸序列进行了聚类分析和序列相似度分析。结果表明, 半滑舌鳎 GnRHR 鳉 与鲈鱼、琥珀鱼、虹鳟以及青 等鱼类中的 GnRHR聚为一支, 亲缘关系较近, 且相似度较高, 分别为 90.1%、 89.7%、 79.0%以及 78.3%, 而与高等哺乳动物人、小鼠相似性仅分别为 18.8%和 16.2%, 亲缘关系较远。应用半定量 RT-PCR 技术分析其组织表达, 发现 GnRHR 广泛表达于各个组织, 但表达量差异较大, 在性腺、脑和肾中表达量较高, 其它组织较弱。 相似文献
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海水仔稚鱼营养研究，特别是在n-3高度不饱和脂肪酸和卵磷脂等方面，国外已取得显著进展。迄今，我国鱼类营养研究基本集中于幼鱼和成鱼阶段，仔稚鱼阶段所见报道甚少。目前，我国养殖的名贵海鱼，其生产性育苗因在仔稚鱼阶段易出现大量死亡，成活率一般低于20%，因而尽快提高海鱼生产性育苗的成活率已成为急需解决的关键问题。
毋庸置疑，仔鱼在从吸收卵黄内源营养转变为摄取轮虫、卤虫等外源营养后，某些营养要素的缺乏、不足是导致仔稚鱼大量死亡的一个重要原因。采用乳化油强化活饵料的方法，在完成n-3高度不饱和脂肪酸对黑鲷仔稚鱼生长、存活影响的基础上(刘镜恪等，1997)，本项研究进一步探讨卵磷脂对真鲷(Pagrus major)仔稚鱼生长、存活的影响。 相似文献
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Diagnosis of iridovirus in large yellow croaker by PCR 总被引：1，自引：0，他引：1
A rapid and sensitive PCR-based method for the detection of the large yellow croaker iridovirus(LYCIV) is described,which involves the amplification of a 295 bp fragment of the LYCIV ATPase gene from DNA isolated from naturally infected fish spleen.Sequencing of LYCIV ATPase gene fragment showed it shared 100% nucleotide sequence homology with the corresponding region of the ATPase gene of red sea bream iridovirus(RSIV) and sea bass iridovirus(SBIV),suggesting that LYCIV was homologous with RSIV and SBIV at least in part of the gemone.The specificity and sensitivity of the PCR procedure were tested on the iridovirus-infected fishes,the expected fragment was detected from spleen DNA samples of infected fishes,whereas no fragments were amplified from healthy fish spleen DNA,white spot syndrome baculoviruses(WSBV) DNA and pseudorabies virus(PRV) DNA.Detection limit of this method was 10-7 ng positive plasmid DNA containing target sequence,equal to about 100 virions.In the infected experiment,first positive detection(1/4) appeared at Day 3 post-infection,all fish(4/4) tested positive at Day 7,however obvious symptoms were observed at Day 8,so LYCIV infection could be detected prior to the appearance of obvious symptoms.These results indicate that this PCR method could be used for early,rapid and specific detection of LYCIV infection. 相似文献
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锦鲤疱疹病毒实时荧光定量PCR检测方法的建立及应用 总被引：2，自引：0，他引：2
研究建立并完善了Taqman实时荧光定量PCR检测锦鲤疱疹病毒（KHV）的方法。首先通过选取KHV病毒TK基因的保守序列（GenBank AB182940）,利用PRIMER EXPRESS 2.0设计引物和探针。其中Taqman探针的5’端标记FAM,3’端标记TAMRA。然后利用梯度稀释的阳性样品克隆质粒进行定量PCR反应,制作标准曲线,得到病毒拷贝数与Ct值的关系为：Ct=-3.45 lgX＋42.73（相关系数R2=0.989）。通过试验检测得到实时荧光定量PCR对KHV的灵敏度为32个病毒核酸拷贝数,同时,设计的引物和探针对于鱼类细胞系和其它鱼类病毒没有扩增反应,表现出较好的特异性。实验结果表明,实时荧光定量PCR检测KHV的方法,具有特异性好、灵敏度高的特点,可以缩短检测时间,提高检测速度,非常适合口岸进出口检验检疫的要求。 相似文献
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Scott AP Katsiadaki I Witthames PR Hylland K Davies IM McIntosh AD Thain J 《Marine environmental research》2006,61(2):149-170
An ELISA for cod vitellogenin (VTG) has been set up using cod lipovitellin for plate coating and standardisation. The assay has been applied to plasma samples collected from male and female cod caught in three distinct areas around the UK, three areas off the Norwegian coast and also to cod reared initially at an aquaculture site and subsequently maintained at a research station. The aim of the study was to determine whether there were any signs of oestrogenic endocrine disruption in a fish species living offshore. VTG induction was found in male cod caught in the North Sea, the Shetland Box area, in Oslofjord and also in cultivated fish. There was a strong relationship between concentrations of VTG and fish size. There was no evidence that the presence of VTG in the plasma of males is a natural part of their life cycle. On the other hand, the size of fish at which these elevated VTG concentrations appear (ca. 5 kg) is about the size that cod change from feeding primarily on benthic invertebrates to mainly other fish, both benthic and pelagic. The possibility is suggested that large cod pick up oestrogenic endocrine disrupters through the food chain. 相似文献
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Robinson CD Craft JA Moffat CF Davies IM Brown ES Megginson C 《Marine environmental research》2004,58(2-5):147-150
Understanding the ecological significance of oestrogenic biomarker responses, seen in field surveys of some UK estuarine fish, requires a suitable model to link biochemical and reproductive effects. The sand goby (Pomatoschistus minutus) is a common inshore fish that has been successfully bred in laboratory aquaria. Juvenile sand goby were continuously exposed to 17beta-oestradiol (E2) during gonadal maturation, and their subsequent reproductive success investigated. Exposure endpoints included hepatic vitellogenin (VTG) mRNA expression and maturation (male nuptial colouration, sperm duct gland- and gonado-somatic indices (SDGSI, GSI)). Reproductive endpoints included spawning behaviour, brood size, fertility and population-level fertile egg production. Measured E2 exposure concentrations were <5 (controls), 17, 71 and 530 ngl(-1). Male maturation decreased with increasing E2 concentration. VTG mRNA expression increased with E2 concentration, but not with duration of exposure. Reproductive endpoints showed progressive impairment with increasing E2 concentration. For most endpoints, the lowest observed effect concentration (LOEC) was 71 ngl(-1), and EC50s were in the range 87-165 ngl(-1). Pre-breeding male colouration, VTG expression and SDGSI were good predictors of subsequent population-level fertile egg production, but GSI was not. The sensitivity of oestrogenic markers in sand goby are comparable to those used in other species, and feral fish populations exhibiting such oestrogenic responses at molecular and organ levels are likely to have reduced fertile egg production. 相似文献
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黄斑篮子鱼去毒相关基因的克隆与肝脏组成型表达分析 总被引：1，自引：0，他引：1
从基因水平探讨海洋鱼类对海洋藻毒素的去毒分子机理。采用RT-PCR法成功克隆了黄斑篮子鱼Siganus oramin肝脏I时相代谢酶细胞色素P450 1A(CYP1A)、II时相代谢酶alpha型谷胱甘肽S-转移酶(GSTA)和rho型谷胱甘肽S-转移酶(GSTR)、热休克蛋白70 (HSP70)、alpha 1型钠钾ATP酶(ATP1A1)及β-肌动蛋白(beta-actin, ACT)基因cDNA核心序列，序列分别长879 bp、582 bp、588 bp、660 bp、749 bp和554 bp。序列同源性分析发现，属鲈形目的黄斑篮子鱼CYP1A、GSTA和GSTR与同属鲈形目的牙鲆Paralichthys olivaceus、欧洲鲽Pleuronectes platessa、真鲷Pagrus major、鲤形目的斑马鱼Brachydanio rerio 相应氨基酸序列同源性较高，CYP1A和GSTA与非洲爪蟾(两栖类)、鸡(鸟类)、小鼠、大鼠和人(哺乳类)相应氨基酸序列同源性低，这可能与鱼类I、II时相去毒酶基因承担水环境毒素去毒代谢的特殊功能有关；而HSP70、ATP1A和β-肌动蛋白在鱼类、两栖类、鸟类、哺乳类中均有较高的同源性，这可能与这些基因在机体中承担的最基本的生命功能相关。应用半定量RT-PCR的方法，以β-肌动蛋白作为外参照，在指数期增长范围内分别得到了CYP1A、GSTA、GSTR、HSP70和ATP1A1 mRNA与β-肌动蛋白mRNA (%)的比值，确定黄斑篮子鱼肝脏去毒相关基因的组成型表达水平。其中，黄斑篮子鱼肝脏CYP1A、GSTA和GSTR基因组成型表达相对较高，HSP70和ATP1A1基因组成型表达相对较低，这可能与不同基因在黄斑篮子鱼海洋藻毒素去毒分子机理中承担的作用相关，为海洋藻毒素在海洋鱼类中的积聚及代谢去毒分子机制的研究提供了相关数据。 相似文献
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Caruso G Denaro MG Caruso R Mancari F Genovese L Maricchiolo G 《Marine environmental research》2011,72(1-2):46-52
Growth, haematological (haematocrit), biochemical (serum cortisol and glucose), and non-specific immune (lysozyme, serum haemolytic and haemagglutinating activities, extracellular respiratory burst activity) parameters, were monitored in European sea bass Dicentrarchus labrax and blackspot sea bream Pagellus bogaraveo subjected to a 31 days starvation compared to fed fish, to assess the responses to feed deprivation of these health status indicators. While haematocrit, serum cortisol, glucose and haemolytic activity of both species did not undergo significant variation following starvation, probably due to the short period applied, some non-specific immune parameters were affected significantly. In the starved sea bass, mucus lysozyme content doubled (1.8 U/mL) compared to the initial value. Haemagglutinating activity was significantly lower in starved sea bass than in fed fish after 31 days. In blackspot sea bream, a slight, not significant, reduction in haemagglutinating activity occurred 11 days after starvation. Respiratory burst activity decreased significantly in the starved fish. In spite of the limited number of examined parameters, the opportunity to use a panel of several indicators to obtain a more complete picture of health status in fish was underlined. 相似文献
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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
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Induction of zona radiata and vitellogenin genes in estradiol and nonylphenol exposed male sheepshead minnows (Cyprinodon variegatus) 总被引：1，自引：0，他引：1
Several genes normally induced by estradiol (E(2)) in female fish, those for vitellogenins (VTGs) and zona radiata proteins (ZRPs), are also inducible in males exposed to estrogenic chemicals. Male sheepshead minnows (SHM) were exposed to both E(2) and para-nonylphenol (NP), at several doses and times to determine a dose-response. Quantitative real time PCR was used to measure mRNA for VTG1, VTG2, ZRP2 and ZRP3. Both E(2) and NP elicited a dose-response increase in all of the mRNAs tested. Exposure to both chemicals resulted in VTG2 expression at about a 10-fold lower level than VTG1, and ZRP2 expression at a lower level than ZRP3. 相似文献
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Several genes normally induced by estradiol (E2) in female fish, those for vitellogenins (VTGs) and zona radiata proteins (ZRPs), are also inducible in males exposed to estrogenic chemicals. Male sheepshead minnows (SHM) were exposed to both E2 and para-nonylphenol (NP), at several doses and times to determine a dose-response. Quantitative real time PCR was used to measure mRNA for VTG1, VTG2, ZRP2 and ZRP3. Both E2 and NP elicited a dose-response increase in all of the mRNAs tested. Exposure to both chemicals resulted in VTG2 expression at about a 10-fold lower level than VTG1, and ZRP2 expression at a lower level than ZRP3. 相似文献
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采用竞争性PCR方法 ,进行 4种营养状况对真鲷脂蛋白脂肪酶 (LPL)基因mRNA表达水平与内脏脂肪蓄积影响的定量研究。结果表明 ,真鲷LPL基因在肝脏存在营养诱导性表达 ,饥饿、高脂食物均是其表达诱导因子 ;在腹腔肠系膜脂肪组织存在组成性表达 ,其表达水平受摄食状态的影响 ,但饲料脂肪水平却不起作用。当真鲷喂食高脂食物时 ,诱导产生的大量肝脏LPL将为肝脏提供更多的来源于食物的游离脂肪酸 ,使肝脏有可能出现营养诱导性脂肪蓄积 ,但真鲷腹腔肠系膜脂肪组织LPL基因表达水平未出现适应性变化 ,其腹腔肠系膜脂肪组织将不可能作为营养诱导性蓄脂器官。由于上述营养状况对真鲷体重、腹脂指数、肝指数均没有产生显著性影响 ,说明真鲷具有在不同营养状况下与哺乳类相似的维持其内脏脂肪蓄积稳定的代谢机制 ,推测真鲷应存在某种在功能上与哺乳类相似的肥胖基因。 相似文献