共查询到20条相似文献，搜索用时 515 毫秒
1.
2.
尽管与性别决定和分化的相关基因在二倍体虹鳟中已被鉴定出来,如Cyp19a1a、Foxl2、Dmrt1、Amh和Sox9,但关于三倍体雌性虹鳟独特性腺表型及其相关性别控制基因的表达规律仍未得到深入研究,尤其是早期卵巢发育阻滞导致的生殖细胞去分化特征。因此,本研究以三倍体雌性虹鳟性腺发育中起重要调控作用的特异候选基因作为重点研究对象,辅助性腺体细胞与生殖细胞分化方向的组织学证据和类固醇激素表达规律,验证了各基因间的级联调控关系。结果表明,虹鳟三倍体与二倍体卵巢的分化特征基本一致。虹鳟二倍体与三倍体性腺分别在84dpf和98dpf就已分化为卵巢。但三倍体虹鳟卵巢分化存在障碍,早期发育停滞,卵原细胞及其滤泡细胞数量有限。Foxl2和Cyp19a1a在二倍体虹鳟卵巢和精巢中均有表达,它们在卵巢中表达量均呈逐渐升高趋势,但在精巢中的表达量非常低;这两个基因在雌性三倍体虹鳟性腺中的表达呈先升高后降低的趋势,其表达量均在8月龄时期达到最大。Dmrt1、Amh和Sox9在二倍体精巢和雌性三倍体卵巢中的表达均呈不断上调趋势,这些基因上调可能与血清睾酮含量的增加相关,因为在10月龄时期这两种鱼的血清含量相对较高,而这三个基因在二倍体虹鳟卵巢中的表达却呈下调趋势。因此本研究认为,维持鱼类卵巢分化需要持续高水平的雌激素,这可能是脊椎动物进化过程中的一个保守特征。可以推断雌性三倍体虹鳟卵巢滞育将导致其体细胞去分化,这对于Cyp19a1a表达及雌二醇合成存在抑制作用。因为这些雌激素是用来维持它们分化和继续发育的,可能产生一个负反馈圈,之后去分化会增强。 相似文献
3.
Effects of petroleum hydrocarbons on the hepatic cytochrome P450 1A1 system in rainbow trout 总被引：1，自引：0，他引：1
Effects on the hepatic cytochrome P450 1A1 system were investigated in juvenile rainbow trout i.p. injected with three different aromatic containing fractions: kerosene, light gas oil or heavy gas oil, originated from distilled North Sea crude oil. Kerosene treatment resulted in no effect on the P450 1A1 system, light gas oil injection caused a weak induction of EROD activities and heavy gas oil treatment resulted in a prominent induction of EROD activities as well as accumulation of CYP1A1 mRNA and P450 1A1 protein levels. The effects of heavy gas oil were compared with effects of β-napthoflavone (β-NF) on the P450 1A1 system. It was obvious that important discrepancies seemed to exist between EROD activities and corresponding CYP1A1 mRNA and P450 1A1 levels in rainbow trout treated with either heavy gas oil or β-NF i.e. heavy gas oil treatment resulted in higher specific EROD activities (EROD/P450 1A1) compared to β-NF. GC-MS analyses revealed that liver and bile from heavy gas oil treated rainbow trout in addition to naphthalene also contained polycyclic aromatic hydrocarbons such as phenanthrenes, anthracene, pyrenes, fluoranthene benz(a)anthracene and chrysene, while none of these compounds were detected in control trout. 相似文献
4.
5.
Cytochrome P-450 isozymes in salmonids determined with antibodies to purified forms of P-450 from rainbow trout 总被引：1，自引：0，他引：1
D.E. Williams R.C. Bender M.T. Morrissey D.P. Selivonchick D.R. Buhler 《Marine environmental research》1984,14(1-4)
Purification of cytochromes P-450 from liver microsomes of β-naphthoflavone (BNF)-fed rainbow trout yielded three apparently homogeneous forms. The major form (LM4b)* appears to be a P-448 type of cytochrome. A minor form (LM4a), having properties very similar to LM4b, was also obtained. In addition, a P-450 form (LM2) was isolated, with properties quite different from LM4a or LM4b, including a high rate of aflatoxin B1 (AFB1) metabolism (Williams & Buhler, 1983c). Antibodies to all three forms were obtained from rabbits. The IgGs prepared against LM4a and LM4b both cross-reacted (forming lines of identity) equally well with both antigens on Ouchterlony plates. Rat P-448 cross-reacted (without lines of identity) with both LM4a- and LM4b-IgG. LM4b-IgG was much more effective than LM4a-IgG for inhibition of LM4a or LM4b reconstituted benzo[a]pyrene (BP) hydroxylase, suggesting that these two antibodies recognize different antigenic sites. The LM2-IgG did not cross-react with any of the other rat or trout cytochromes P-450 examined. Levels of LM2 and LM4b in microsomes from untreated, polychlorinated biphenyl (PCB), phenobarbital (PB) or BNF-treated trout were estimated with an immunological technique involving electrophoresis on SDS-PAGE, followed by transfer to nitrocellulose and staining with either LM 2 - or LM4b -IgG. The ratio of
in microsomes from PCB- or BNF-treated rainbow trout was much higher than 1, whereas the reverse was true with microsomes from untreated rainbow trout. These results are consistent with previous observations (Vodicnik et al., 1982) that pretreatment with BNF induced the synthesis of a P-448 type cyytochrome, presumably responsible for the great increase in the metabolism and activation of BP seen in these fish. Conversely, pretreatment with PB did not affect the levels of either LM2 or LM4b. This specific immunological technique should make it possible to assay the levels of these P-450 and P-448 isozymes in various strains of rainbow trout and other species of fish. In addition, the effect of age, sex, diet and exposure to P-450 and P-448 inducers could be examined and, perhaps, utilized to predict the relative risk of certain populations to pollutants activated by these different isozymes. 相似文献
6.
几种鲑鳟鱼血清蛋白非变性聚丙烯酰胺凝胶电泳的研究 总被引：1，自引：0，他引：1
采用非变性聚丙烯凝胶电泳的方法分析了硬头鳟、金鳟、虹鳟、北极红点鲑和溪红点鲑血清蛋白的组成成分及其含量。结果显示, 硬头鳟、金鳟和虹鳟三者之间的遗传距离最小, 硬头鳟、金鳟和虹鳟三者与溪红点鲑的遗传距离最大; 硬头鳟、金鳟和虹鳟三者与北极红点鲑处于同一亚组, 而溪红点鲑独处于另一亚组。研究结果表明硬头鳟、金鳟和虹鳟三者与溪红点鲑的亲缘关系远于与北极红点鲑的关系; 同时还表明, 以聚丙烯酰胺凝胶电泳分析鲑鳟鱼血清蛋白的方法简单易行、重复性好。本研究结果对鲑鳟鱼的种属鉴定、良种选育、品种改良和遗传结构分析提供了试验依据; 虹鳟的繁养殖需进一步规范化和标准化, 减少蛋白遗传基因的流失, 从根本上预防大规模疾病的暴发。 相似文献
7.
本文研究了不同盐度驯化方式下虹鳟(Oncorhynchus mykiss,(99.44±0.26)g(简写为99 g))和两种规格硬头鳟(Oncorhynchus mykiss,(99.01±0.61)g(简写为99 g)和(394.50±1.16)g(简写为395 g))的血清抗氧化酶活性变化。实验设置4种盐度驯化方式:淡水对照组(T0组);从淡水直接过渡到盐度30(T30组);从淡水直接过渡至盐度14,然后以升盐速度2/d(T2组)和6/d(T6组)至盐度30。盐度驯化结果显示:99 g硬头鳟和虹鳟血清中超氧化物歧化酶(SOD)、丙二醛(MDA)和谷胱甘肽过氧化物酶(GSH-Px)活性均受盐度驯化方式、时间及其交互作用影响显著。T30组99 g虹鳟和99 g硬头鳟的SOD、GSH-Px和MDA活性在0.5、1、4、8、15和40 d这6个取样点均显著高于对照组(P<0.05)。盐度驯化40 d后,T2组99 g虹鳟SOD活性、GSH-Px活性和MDA含量与对照组无显著差异,99 g硬头鳟GSH-Px活性与对照组无显著差异,T6组99 g虹鳟和99 g硬头鳟的SOD和GSH-Px活性显著高于对照组。T2组395 g硬头鳟SOD活性、过氧化氢酶(CAT)活性和MDA含量与对照组相比无显著差异(P>0.05),而T6和T30组395 g硬头鳟血清中SOD活性、CAT活性、GSH-Px活性和MDA含量显著高于对照组(P<0.05)。研究结果表明,T2组渐变盐度方式更适合虹鳟和硬头鳟盐度驯化,395 g硬头鳟对盐度驯化的适应能力优于99 g硬头鳟。 相似文献
8.
Thomas T Chen 《Marine environmental research》1988,24(1-4)
In recent years, there has been increasing concern as to the potential health effects of polyhalogenated and/or polynuclear aromatic hydrocarbons, since these environmental xenobiotics have been associated with reproductive dysfunction in a variety of wildlife. Studies are described here on the development of molecular biological parameters for: (i) the investigation of toxic mechanisms of environmental xenobiotics at sublethal levels; and (ii) the screening of any other toxic chemical pollutants in the aquatic ecosystems. Through molecular cloning, cDNA of estrogen-responsive genes and growth hormone gene of rainbow trout have been isolated. In appropriate rainbow trout primary or established cell culture systems, these cDNA clones can be used as molecular probes for the elucidation of molecular toxic mechanisms of environmental xenobiotics. 相似文献
9.
Kim IC Chang SY Williams TD Ja Kim Y Yoon YD Lee YS Park EH Lee JS 《Marine environmental research》2004,58(2-5):687-691
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
10.
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
11.
12.
Effects of cadmium exposure on plasma levels of calcitonin and free and protein-bound calcium were studied in vitellogenic female rainbow trout kept in brackish water (7%(.)). Fish were exposed to 100 μg cadmium litre−1 for four weeks. Exposure of female rainbow trout in the stage of vitellogenesis, with increased total plasma levels of calcium, resulted in a complex hypocalcemic response. Thus, hypocalcemia was found to be due to three different processes: (1) a decrease in the free plasma calcium, and a reduction in protein-bound calcium; due both to (2) decreased plasma levels of vitellogenin; and (3) a reduced binding of calcium to vitellogenin. These findings support the concept of an interference of cadmium with ionregulating tissues as a mechanism for hypocalcemia in rainbow trout. A direct effect on the vitellogenin-binding of calcium was also observed and reproductive function in the females was affected by decreased plasma levels of vitellogenin. In spite of the marked changes of plasma calcium in exposed fish, no significant effects on plasma calcitonin were observed, indicating a lack of a direct relationship between plasma calcium and calcitonin levels in rainbow trout. 相似文献
13.
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
14.
This study examined the diet of sympatric populations of migratory juvenile rainbow trout and landlocked koaro in the Waipehi and Omori Streams, Lake Taupo, New Zealand. In both species, diet was dominated, both numerically and by weight, by aquatic prey: Ephemeroptera, Trichoptera, and Diptera larvae were the most numerous prey items. Adult koaro and juvenile rainbow trout both fed on small koaro. Terrestrial prey items were present in low numbers in the diets of both koaro and juvenile rainbow trout, but were more important in terms of weight. Resource partitioning was weak although koaro consumed more small benthic invertebrates such as chironomid larvae, whereas the diet of rainbow trout contained more Ephemeroptera larvae and terrestrial insects. In the Waipehi Stream, koaro consumed both rainbow trout ova and koaro ova; in Omori Stream, trout ova were important in the diet of juvenile rainbow trout. Since the diets of koaro and juvenile rainbow trout in some Taupo tributaries are similar, populations may co‐exist by temporal and/or spatial partitioning of food resources, whereas trout predation on small koaro may be a limiting factor for koaro populations. 相似文献
15.
Il-Chan Kim Sung Yeoul Chang Tim D. Williams Young Ja Kim Yong-Dal Yoon Yong-Sung Lee Eun-Ho Park Jae-Seong Lee 《Marine environmental research》2004,58(2-5):687
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
16.
Christer Erséus 《新西兰海洋与淡水研究杂志》2013,47(4):557-561
We characterised seasonal and ontogenetic changes in diet and prey energy density of rainbow trout (Oncorhynchus mykiss) in Lake Rotoiti, New Zealand, to better understand the prey requirements of trout in central North Island lakes. Common smelt (Retropinna retropinna) was the dominant prey item of rainbow trout larger than 200 mm (77.8% of diet by weight), followed by kōura (freshwater crayfish Paranephrops planifrons; 6.3%), common bully (Gobiomorphus cotidianus; 5.5%), and kōaro (Galaxias brevipinnis; 3.4%). Juvenile rainbow trout (<200 mm) consumed amphipods, aquatic and terrestrial insects, oligochaetes, tanaid shrimps, and smelt. Trout consumed kōaro only in autumn and winter; consumption of other species did not vary seasonally. The maximum size of smelt consumed increased with increasing trout size, but trout continued to consume small smelt even as large adults. Consumption of larger prey items (kōaro and kōura) also increased with increasing trout size. This study indicates the importance of smelt for sustaining rainbow trout populations, as predation on other species was relatively low. These findings provide a basis for bioenergetic modelling of rainbow trout populations in lakes of the central North Island of New Zealand. 相似文献
17.
The purpose of the present study was to assess the in vitro effect of some imidazole (prochloraz, imazalil) and triazole (epoxiconazole) agricultural fungicides on gonadotropin-induced oocyte maturation in rainbow trout. Results show that prochloraz, epoxiconazole and imazalil strongly potentiated the induction of oocyte maturation by gonadotropin in a dose-dependent manner. Furthermore, 10(-5) M prochloraz and epoxiconazole alone induced oocyte maturation. The mRNA biosynthesis inhibitor, actinomycin d, completely inhibited oocyte maturation induced by fungicides, suggesting that the gonadotropin-like effect of these chemicals is at least dependent on de novo gene expression. 相似文献
18.
The toxic effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and its related planar halogenated aromatic hydrocarbons (PHAHs) are mediated by the aryl hydrocarbon receptor (AHR). To investigate the potential sensitivity to PHAHs and the evolutional diversity of AHR in aquatic birds, AHR cDNAs were initially cloned and sequenced from the livers of a black-footed albatross (Diomedea nigripes) and a common cormorant (Phalacrocorax carbo). In this study, we report the identification of two distinct AHR paralog genes in these species. The two full-length AHR cDNAs from albatross were highly divergent (33% overall amino acid identity, and 60% identity in the N-terminal half). Phylogenetic analysis showed that one of them belongs to the AHR1 clade and the other one to the AHR2 clade, which has been identified only from fishes, but not yet from mammals and birds. Albatross AHR1 encoded a 861-residue protein with a predicted molecular mass of 96.7 kDa, and in the case of albatross AHR2, 925 amino acids and 100.7 kDa. From cormorant liver, the full-length AHR1 cDNA and the partial AHR2 cDNA were cloned. This result strongly suggests that bird species also possess two distinct AHR genes (AHR1 and AHR2). To our knowledge, this is the first report on the presence of an AHR2-like isoform in bird species as well as in fish. 相似文献
19.
Carbonyl reductase (CBR) is an enzyme involved in protection from oxidative stress. In rainbow trout (Oncorhynchus mykiss), the hepatic mRNA abundance of the two isoforms (A and B) is increased after exposure to treated sewage effluents, as well as after exposure with β-naphthoflavone (β-NF) and the pro-oxidant paraquat. In this study, we show that the same chemicals similarly increase the single known hepatic CBR mRNA level and CBR catalytic activity in the coastal living eelpout (Zoarces viviparus). Hepatic CBR mRNA abundance and catalytic activity were also compared between eelpout collected at contaminated and reference sites on the Swedish west coast, but no differences were observed. In conclusion, CBR is a potential biomarker candidate for monitoring the exposure and effects of AhR agonists and/or pro-oxidants in the marine environment, but more research is needed to investigate temporal regulation as well as dose dependency for different chemicals. The mRNA and enzymatic assays presented in this study provide two additional tools for researchers interested in expanding their biomarker battery. 相似文献
20.
Expression of flavin-containing monooxygenase(s) (FMO) correlates with salinity exposure in certain species of euryhaline fish, such as the rainbow trout, Oncorhynchus mykiss. The mechanism(s) by which salinity regulates FMO is unclear. Adult rainbow trout were infused through the dorsal aorta with either cortisol or urea. At 500 ng/ml, cortisol caused a significant increase in FMO-catalyzed thiourea oxidase activity in gill and liver microsomes. FMOI expression, however, was significantly increased by the high cortisol dose only in gill microsomes. The levels of TMAO and urea were not altered by cortisol. In the liver, urea infusion caused an increase in hepatic FMO activity. FMO expression and activity correlated with elevated tissue urea levels, but TMAO concentrations were not related. These results indicate that FMO expression and activity may be partially controlled by the osmoregulatory/stress hormone. cortisol, and concentrations of the organic osmolyte, urea, in the rainbow trout. 相似文献