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To use two small fish Rivulus marmoratus (Cyprinodontiformes, Rivulidae) and the Japanese medaka Oryzias latipes (Belloniformes) as testing models in molecular ecotoxicology, we have cloned the cytochrome P450 1A (CYP1A) gene after screening of both genomic DNA libraries, and sequenced 11,863 and 7,243 bp including all the exons and introns with promoter regions, respectively. The Rivulus and the medaka CYP1A gene consisted of seven exons (including non-coding exons) with high homology to mammals. In the promoter region, Rivulus CYP1A gene has seven xenobiotic response elements (XREs) and two metal response elements (MREs), while the Japanese medaka CYP1A gene has six XREs and four MREs. Interestingly, medaka CYP1A gene has a number of MREs at the promoter, which may affect its response on metal exposure. We describe here the gene structure of both fish CYP1A genes.  相似文献   

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The cytochrome P450 1 (CYP1) family has expanded with the addition of the CYP1B and CYP1C subfamilies. We recently identified a new CYP1 subfamily in zebrafish, CYP1D, with a single gene, CYP1D1. Here we examined sequences found in other fish genomes, i.e., stickleback (Gasterosteus aculeatus) and medaka (Oryzias latipes), for similarities among fish CYP1D1 genes. The full-length deduced amino acid sequences for CYP1D1 in these two species averaged about 43% identity to the CYP1As, but nearly 50% when sequence alignment ambiguities were masked. CYP1D1 has seven exons, similar in size and position to the exons in CYP1D1 and CYP1A in zebrafish. However, the intronic distances were substantially smaller in the medaka and stickleback. There also were differing numbers of putative xenobiotic response elements in the CYP1D1 of the various species. Whether the stickleback or medaka genes are inducible by aryl hydrocarbon receptor (AHR) agonists is yet to be determined.  相似文献   

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Mytilus galloprovincialis digestive gland microsomes were prepared from (i) indigenous populations sampled from a clean reference (Lido) and an urban-contaminated site (Salute) and (ii) mussels transplanted for up to 3 weeks from Lido to an industrial-contaminated site (CVE) in Venice Lagoon, Italy. Western blot analysis was performed using antibodies to five mammalian or fish CYP forms (1A, 2B, 2E, 3A, 4A). Simultaneously run M. edulis digestive gland partially purified CYP aided identification of immunopositive bands. Levels of CYP1A, CYP2E, and CYP4A-immunopositive proteins were 50 to 300% higher in indigenous M. galloprovincialis from Salute compared to Lido (p < 0.05). Three weeks after transplantation to CVE, levels of only the CYP1A-immunopositive protein were determined to be higher (63%) than levels for Lido (p < 0.05), indicating that anti-CYP1A shows greater specificity for a contaminant-inducible CYP form than the other antibodies.  相似文献   

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鳜(Siniperca chuatsi)、大眼鳜(Siniperca kneri)、斑鳜(Siniperca schezeri)为鳜属中3种主要经济鱼类,具有较近的亲缘关系和相似的生活习性,但生长性状差异较大.为探索3种鳜鱼生长差异与基因差异间联系,以野生群体为材料,采用PCR扩增、电泳及测序等方法,对生长发育相关基因生长激素(GH)基因进行了多态性检测与分析.在第一内含子、第二内含子前段、第二内含子中段微卫星序列及第三内含子中均检测到多态性.各区域共检测到25种长度类型,其中4种为鳜与大眼鳜共有长度类型,3种为鳜、大眼鳜与斑鳜共有长度类型,其余18种为各物种特有长度类型.各区域长度类型共组成14种单倍型,无种间共有单倍型.序列长度差异主要由重复序列及DNA片段的插入或缺失形成.在第1内含子3'端-6位与第3内含子5'端+16位各发现一处靠近剪接位点的序列差异.根据多态性检测结果构建系统发育树,鳜与大眼鳜先聚为一枝.本研究可为进一步确认鳜鱼GH基因差异与生长性状间联系,并利用基因差异进行鳜鱼种质资源保护及分子育种奠定基础.  相似文献   

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The relationship between cytochrome P450 and feeding on terpenoid-rich gorgonian corals was investigated in a species of tropical butterflyfish and compared with two other sympatric congeners that do not feed on gorgonians. Fish were collected from non-polluted waters in Belize and the levels of two cytochrome P450 isozymes (CYP2B and CYP3A) were immunoquantitated in addition to quantification of total P450. Chaetodon capistratus regularly feeds on gorgonian corals and has higher levels of total hepatic microsomal cytochrome P450 than C. ocellatus or C. striatus. The content of hepatic P450 (0.588–0.794 nmol mg−1) in C. capistratus is among the highest ever reported in teleosts from non-polluted waters and is significantly greater than detected in C. ocellatus or C. striatus. Chaetodon capistratus also had a larger hepatic index (g liver per g fish) and more microsomal protein (mg protein per g liver), factors that translate into 3.3- to 8-fold more total P450 per g fish. Sexual differences in total P450 were observed between male and female C. capistratus, but not among the other species. The contents of proteins detected by immunoassay with polyclonal anti-scup P450B (CYP2B) and anti-human P4503A (CYP3A) were 2- to 10-fold and 2- to 20-fold greater, respectively, in C. capistratus than in the congeneric species. CYP2 and CYP3 gene families in mammals are thought to have evolved partially in response to dietary allelochemicals. These results suggest that these P450 isozymes may also be important in marine teleosts that feed on terpenoid-rich prey.  相似文献   

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Induction of hepatic cytochrome P450-dependent microsomal mono-oxygenase by xenobiotics is a well-established phenomenon in teleost fish. As in laboratory mammals, fish possess multiple forms of cytochrome P450 that display overlapping substrate specificity. One such isoform, CYP1A1, which has been cloned and sequenced from rainbow trout, has been shown to be orthologous to rat CYP1A1 and, as in mammals, is inducible up to several hundred-fold by planar aromatic hydrocarbons, PCBs and dioxins. It has been suggested that induction of CYP1A1 orthologues might provide a sensitive biomonitor for environmental pollution by mixtures of such compounds. In the current study, polyclonal antibodies directed against CYP1A1 purified from rat and trout liver were used to monitor induction of the CYP1A1 orthologue in hepatic microsomes from the fresh water species, the channel catfish (Ictalurus punctatus). Catfish from a local fish farm were induced in the laboratory by three daily injections of 50 mg/kg of the PCB mixture Aroclor 1254 and compared with fish taken from a site in central Arkansas—the Bayou Meto, known to be polluted with dioxin. Hepatic microsomal activities towards ethoxyresorufin (EROD) and pentoxyresorufin (PROD) were measured and Western blot analysis carried out with the two antibodies. EROD was elevated in both the Aroclor-treated fish and in the Bayou Meto fish compared with untreated fish farm controls; smaller but significant increases were observed in PROD. Spearman's rank correlations of 0·74 and 0·89 were observed between EROD and immunoquantified cross-reactivity towards the rat CYP1A1 and trout CYP1A1 antibodies.  相似文献   

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The contaminant-induced cytochrome P450 (CYP) members in minke whale (Balaenoptera acutorostrata) can be potential biomarkers of the contaminant exposure and toxic effects. In this study, we constructed a cDNA library from the liver of minke whale from the North Pacific, and further screened a total of 6930 clones randomly selected in the library for the isolation of cDNA clones encoding novel members of CYP superfamily. The screening revealed the isolation of six novel CYP cDNA clones that are classified into CYP1A, CYP2C, CYP2E, CYP3A, CYP4, and CYP4A subfamilies. The BLAST homology search using the partial cDNA fragments of four CYP subfamilies (CYP1A, CYP2C, CYP2E and CYP4A) demonstrated that the minke whale CYPs were most closely related to pig CYPs (81-91%). Identification of multiple CYP genes in marine mammal species such as minke whale will provide new insights into the metabolic or toxicological functions of individual CYP members.  相似文献   

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Recent advances in molecular immunology indicate that the expression of inducible pro-inflammatory proteins is increased in vertebrates in response to both infectious disease agents and various xenobiotics. For example, iNOS, COX-2, and CYP1A are induced by both inflammation and AhR ligands. Moreover, the expression of these proteins in response to stimuli varies among individuals within populations. Little is known of the differences among fish in the inducibility of proinflammatory proteins in response to both infectious agents and xenobiotics. Through random screening of a striped bass, Morone saxitilis, peritoneal macrophage cDNA library, a full length metallothionein (MT) gene was cloned and sequenced. MT is a low-molecular weight (6–8 kDa), cysteine-rich metal binding protein. Metals are required by pathogenic bacteria for growth, and by the host defense system by serving as a catalyst for the generation of reactive oxygen intermediates (ROIs) by phagocytes. A recombinant striped bass MT (rMT) was expressed and purified, then used to generate a specific mAb (MT-16). MT protein expression was followed in freshly isolated striped bass and channel catfish, Ictalurus punctatus, phagocytes after in vitro exposure to the naturally occurring intracellular pathogen Mycobacteria fortuitum or to 0.1 and 1 μM mercury (Hg), as HgCl2. MT expression was increased by 24 h in both channel catfish and striped bass phagocytes as a result of exposure to M. fortuitum cells. On the other hand, MT was induced by Hg in channel catfish cells, but not those of striped bass. These results indicate that metal homeostasis in phagocytes is different between catfish and striped bass. In addition, these data suggest that care should be taken to distinguish between inflammation-induced vs. metal-induced MT when using MT expression as a biomarker of metal exposure.  相似文献   

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The carbamate pesticide, aldicarb, demonstrates significant acute toxicity in fish, and is readily biotransformed by most organisms studied. In fish, both the cytochrome P450 (CYP) and the flavin monooxygenase systems (FMO) are involved in bioactivating aldicarb to aldicarb sulfoxide, which is a more potent inhibitor of acetylcholinesterase (AChE). Channel catfish (Ictalurus punctatus), along with many other fresh water species, do not express FMO and are relatively resistant to the effects of aldicarb. This project examined the toxicity, AChE inhibition, metabolism, and toxicokinetic of aldicarb in channel catfish, and compared these values with an aldicarb-sensitive species, rainbow trout, which expresses FMO. Studies of in vitro and in vivo aldicarb biotransformation in catfish suggest that a low rate of bioactivation (10 times slower Vmax), resulting in less initial conversion to the activated metabolite, aldicarb sulfoxide, may be a contributing factor to resistance of channel catfish to aldicarb toxicity. These data are supported by toxicokinetic and enzyme inhibition studies. This work demonstrates that differences in FMO expression among fish species may have significant influence on toxicity resulting from exposure to some xenobiotics.  相似文献   

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线粒体基因组已被广泛应用于后生动物分子系统发育和群体遗传的研究。文昌鱼(Amphioxus)作为研究脊椎动物起源和进化的模式动物,在脊椎动物起源和进化研究中占据极为重要的位置。作者综合分析文昌鱼2科7个种的51条线粒体基因组全序列,全面揭示了文昌鱼线粒体基因组的基本特征。文昌鱼线粒体基因组均编码后生动物标准的37个基因...  相似文献   

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Cytochrome P450 monooxygenases constitute an enzyme superfamily, with at least 74 known families. Members of CYP families 1–4 are important in the phase 1 metabolism of lipophilic xenobiotics, such as those found in contaminated marine environments. Previous studies (James et al. Arch. Biochem. Biophys. (1996) 329, 31–38) showed that a major form of P450 in spiny lobster, Panulirus argus, hepatopancreas was CYP2L1, a new sub-family, and that there was evidence for other P450 forms in hepatopancreas. We now report the sequence of a second member of this subfamily, named CYP2L2, present in P. Argus hepatopancreas. The deduced amino acid sequences of CYP2L1 and CYP2L2 share 54.7% sequence identity and an additional 13.6% of the sequences show conservative substitutions. Analysis of the sequences of CYP2L1, CYP2L2 and other representative CYP2 family members (from rat and mouse sub-families 2A, 2B, 2D and 2E) showed that the crustacean sequences clustered together. In addition to CYP2L2, cDNA clones of 66 to 117 base pairs from the 5′ coding region of two more P450 isoforms were isolated from the spiny lobster cDNA library. The deduced amino acid sequence of one of these additional cDNA clones was identical to the first 22 amino acids of the N-terminal sequence of a P450 protein previously isolated from hepatopancreas microsomes. These studies confirm earlier biochemical evidence that the hepatopancreas contains multiple forms of cytochrome P450.  相似文献   

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采用胸腔注射植物凝集素(PHA)、秋水仙素,以大刺鳅(Mastacembelus armatus)头肾组织为材料,低渗处理,空气干燥法进行染色体标本制备,分析其染色体核型。结果显示:大刺鳅的二倍体染色体数目为2n=48,其核型公式为2n=14m+34t, NF=62。对24尾大刺鳅线粒体Cyt b基因和D-loop序列进行测序分析,结果表明:(1)大刺鳅Cytb基因、D-loop序列长度分别为1438bp、895bp,两个基因的单倍型多样性分别为0.656和0.541,核苷酸多样性分别为0.00539和0.00817,平均核苷酸差异数分别为5.938和6.805,说明该种群的遗传多样性丰富。(2)两个基因的每个个体的遗传距离分别为0.000—0.018和0.000—0.026,说明该种群个体间的遗传距离小。(3)中性检验的Tajima’sD检验及Fu's Fs检验的结果说明该种群没有发生过扩张。结果说明北江大刺鳅的遗传多样性水平较高,可用于人工繁育。  相似文献   

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We cloned the vitellogenin gene from the self-fertilizing fish Rivulus marmoratus, and sequenced 12,326 bp. The number of exons of R. marmoratus and rainbow trout vitellogenin genes were different, and also the splicing junctions are different throughout most of the exons and introns but the amino acid similarity of R. marmoratus vitellogenin gene to other species was rather high. In promoter region of R. marmoratus vitellogenin gene, there were several E2 binding sites and the estrogen response element (ERE). We discuss here the gene structure and expression of R. marmoratus vitellogenin gene.  相似文献   

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This study provides one of the first quantitative assessments of a fish community within a pre-operational deep-water port system. Between September 2006 and September 2007 a total of 4 559 fish, representing 47 species and 27 different families, were caught within the Port of Ngqura, Africa's deepest port, in 1 713 h of shore-angling (2.3 fish angler?1 h?1) and 239 h of boat-based angling (2.8 fish angler?1 h?1). Catches included species representative of both estuarine and shore fisheries. The majority (83.0%) of species caught were marine and most were less than size-at-50% maturity (71.4%). The most abundantly caught species were dusky kob Argyrosomus japonicus (25.5%), elf Pomatomus saltatrix (24.9%), garrick Lichia amia (17.7%) and dusky sharks Carcharhinus obscurus (10.7%). Fish assemblages differed significantly (p < 0.05) between three habitats within the port: Dolosse, Quay Wall and Sandy Shore. The Dolosse habitat supported the greatest abundance (3.1 fish angler?1 h?1) and diversity (43) of fish species. The Port of Ngqura is thus functioning as an important habitat for both juvenile and adult fish. The diversity and abundance of fish suggests the potential use of ports and other artificial structures for enhancing local fisheries in South Africa.  相似文献   

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