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Hayes RA Regondi S Winter MJ Butler PJ Agradi E Taylor EW Kevin Chipman J 《Marine environmental research》2004,58(2-5):665-669
Metallothionein has been assayed in a range of aquatic animal tissues as an indicator of metal exposure. We sequenced chub (Leuciscus cephalus) metallothionein cDNA which showed over 90% homology to common carp, goldfish and stone loach and 77% homology to rainbow trout sequences for metallothionein. We then used the extended primer method to develop an accurate quantitative competitive RT-PCR assay for metallothionein mRNA. RT-PCR was used to measure metallothionein mRNA in feral chub from a range of field sites, with different levels of heavy metal pollution, in the West Midlands, UK. Measurements were complemented by analysis of liver and gill metallothionein protein by capillary electrophoresis. There was no significant difference in the metallothionein protein levels between fish of different rivers and there was no evidence of elevation of mRNA at the sites of highest metal exposure. The level of metal exposure (e.g. zinc, nickel and cadmium each ranging between 15 and 28 microg/l ) at the pH (7.5-8.5) of these rivers appears insufficient to elevate hepatic or gill metallothionein in chub. A lack of elevation of hepatic metallothionein mRNA in chub exposed to zinc, copper and manganese for 24 h and 10 days in the laboratory also suggests a non-responsiveness of this species. 相似文献
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23.1 介绍 模拟与频率和方向相关的大洋波谱F(f,θ)的工作是极其困难的。唯一有点统一的理论(Hasselmann,1967)也还没有简化成一种实用形式。这篇研究中所探讨的是结合零散的,现有的理论,以达到这样一种目的:即发展一种与我们目前对风浪成长谱的了解相一致 ·95.的波谱模式。本章中我们将讨论一种离散的谱模式,这种模式采用了一种改进的能量传播的特征方法。数值方法最早是由Barnett等(1969)提出的。 相似文献
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Bioaccumulation of Cd, Co, Cu, Ni, Pb and Zn in Antarctic gammaridean amphipod collectives, Orchomene plebs (Hurley, 1965), was investigated during a cruise of RV "Polarstern" to the Wedell Sea. With the sole exception of Cd the organisms accumulated metals during exposure and depurated them in uncontaminated seawater. Four independent toxicokinetic experiments and one field study were modelled simultaneously to calculate the following size-dependent bioconcentration factors for organisms with body length 10 mm (BCF(10 mm)): 130 (Co), 4030 (Cu), 190 (Ni), 2900 (Pb), and 5210 (Zn). On the time scale of our experiments the data suggest an increased metal uptake by previously exposed test organisms. The collectives investigated may be regarded as potentially suitable biomonitors for Co, Cu, Ni, Pb and Zn but not for Cd. An approach to evaluate the sensitivity of Orchomene plebs as a biomonitor of waterborne metals in the field indicates minimal increments of the ambient exposure concentrations of 0.01 microg Co l(-1), 0.2 microg Cu l(-1), 0.4 microg Ni l(-1), 0.6 microg Pb l(-1) and 0.3 microg Zn l(-1). 相似文献
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Induction of vitellogenin in vivo and in vitro in the model teleost medaka (Oryzias latipes): comparison of gene expression and protein levels 总被引:5,自引:0,他引:5
Quantification of the egg yolk precursor vitellogenin (VTG) in fish has become a standard technique to detect estrogenic effects of known chemicals and environmental samples. In the present study, we have analysed VTG induction by estradiol, ethynylestradiol and genistein exposure in the model teleost medaka (Oryzias latipes) and demonstrate that the medaka is a suitable model system to analyse estrogenic effects. By comparing VTG gene expression and protein levels we show that in principal both techniques can be used to study VTG induction in vivo (juvenile and adult males) and in vitro (primary cultures of male liver cells). If a short term in vivo or in vitro exposure is performed, detection of mRNA might be sufficient. For long term studies with the need to detect weak estrogenic chemicals and a precise quantification, immuno-chemical detection may be favoured. 相似文献
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海带雌配子体对吲哚乙酸反应的初步观察 总被引:3,自引:0,他引:3
吲哚乙酸(IAA)对高等植物细胞的刺激作用已有不少研究。它对某些藻类的效应也有一些观察。例如Provasoli(1958)的实验指出,低剂量吲哚乙酸对石尊(Ulva lactuca)有刺激生长的作用,浓度较高时(0.3mg/升)则有抑制作用。Conrad等的实验指出,吲哚乙酸(3mg/升)可以促进丝藻(Ulothrix subliblssima)的生长,提高湿重13倍。 相似文献
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不同水温对文昌鱼性腺发育的影响 总被引:10,自引:1,他引:10
研究表明,不同水温对文昌鱼性腺发育分化和成熟有十分显著的影响。14℃对文昌鱼性腺发育没有显著的作用,20和25℃十分有利于性腺发育和成熟,经40d培养,出现一些雌、雄文昌鱼产卵和释精以及加速性腺发育。本文还讨论了水温促进性腺发育可能的机制。 相似文献