三疣梭子蟹体内苯并[a]芘的富集动力学

采用半静态双箱动力学模型研究三疣梭子蟹(Portunus trituberculatus)对苯并[a]芘(benzo[a]pyrene,BaP)的生物富集,通过对富集与排出过程中三疣梭子蟹体内BaP的动态监测,并对监测结果进行非线性曲线拟合,得到三疣梭子蟹的吸收速率常数K1、排出速率常数K2、生物富集因子BCF、富集平衡浓度CAmax、生物学半衰期B1/2等动力学参数;拟合结果得到BaP的各动力学参数分别如下:K1为14.67~26.08、K2为0.09~0.14、CAmax为9.31~73.35、BCF为163.00~196.29、B1/2为4.95~7.70 d。对模型的拟合优度检验结果显示,在BaP暴露条件下三疣梭子蟹对BaP的生物富集数据符合双箱动力学模型,模型的拟合优度良好。比较结果得出:三疣梭子蟹对不同浓度的BaP吸收速率常数K1及生物富集系数BCF基本随外界水体中暴露浓度的增加而降低;排出速率常数K2与外界水体暴露浓度无明显关系;理论平衡条件下生物体内BaP含量CAmax随着外界水体中BaP暴露浓度的增加而增大,且基本成正相关。实验结果表明BaP暴露条件下双箱动力学模型在一定条件下是可以应用于三疣梭子蟹的富集动力学研究的。     

高效液相色谱法(High Performance Liquid Chromatography)检测烟熏大黄鱼Pseudociaena crocea(Richardson)中苯并[a]芘(Benzo(a)pyrene)

本文研究了烟熏大黄鱼样品中苯并[a]芘残留的提取、净化和高效色谱分析条件。建立了高效液相色谱法测定烟熏大黄鱼中苯并[a[芘残留的方法。该法检出限为0．1g／kg。回收率为76％-96％。     

苯并[a]芘(BaP)急性暴露对泥蚶消化腺的毒性效应及其应对机制初探

本文研究了苯并[a]芘(benzo[a]pyrene, BaP)急性暴露对泥蚶(Tegillarca granosa)的毒性效应,并以泥蚶的消化腺为目标组织,对泥蚶抵抗BaP毒性的机制进行了初步探究。对样本进行HE染色并对所采集的图像进行分析处理,结果发现,暴露于BaP导致泥蚶消化腺组织出现坏死。对样本进行脂质过氧化并进行DNA氧化损伤测定的结果显示,暴露于BaP导致泥蚶消化腺氧化压力增加,进而导致脂质过氧化以及DNA氧化损伤等细胞层面的损伤。抗氧化酶活性测定结果显示,BaP胁迫诱导泥蚶产生氧化应激反应,抗氧化防御体系积极参与BaP诱导的氧化应激调控过程。神经毒性指标测定结果显示,BaP胁迫可能影响泥蚶神经冲动的传导而具有神经毒性。此外,DNA甲基化水平测定及抗氧化酶基因表达测定的结果显示,泥蚶可能通过降低DNA甲基化水平来激活抗氧化系统以对抗BaP毒性。综上所述,急性BaP暴露会对泥蚶产生显著的毒性效应,以组织损伤、氧化应激反应和神经毒性为主要表征;泥蚶可能通过调整自身DNA甲基化水平来对抗BaP毒性效应。通过本研究,有望为深入探索双壳贝类应对石油污染物胁迫的内在调控机制提供新思路,同时为石油污染威胁下泥蚶的生物资源保护提供参考。     

苯并_a_芘对大弹涂鱼肝脏芳烃羟化酶活性的影响

研究了苯并(a)芘(BaP)胁迫下大弹涂鱼肝脏芳烃羟化酶(AHH)活性的变化,结果显示BaP对大弹涂鱼肝脏AHH活性总体表现为显著的诱导作用(P＜0.01),其中BaP暴露的浓度及时间是影响AHH活性的重要因素.0.05mg@L-1浓度的BaP暴露对AHH活性无显著影响,而0.2mg@L-1和0.5mg@L-1浓度组AHH活性则显著被诱导(P＜0.01).随着暴污时间的延长,0.2mg@L-1浓度组AHH活性被显著诱导(P＜0.01),而0.5mg@L-1组AHH活性则相对稳定.对AHH活性变化的剂量-效应关系进行回归分析的结果表明,0.5mg@L-1浓度组暴露7d时,AHH活性受到一定程度的抑制.污染解除后,0.5mg@L-1浓度组AHH活性显著降低,恢复至与对照组相近,表明大弹涂鱼肝脏仍具有较强的生理调节机能,同时也表明AHH活性可及时反映环境中BaP的水平.以上这些结果表明AHH适于作为大弹涂鱼受BaP胁迫的生物指标.     

苯并（a）芘对大弹涂鱼肝脏谷胱甘肽过氧化物酶活性的影响

研究大弹涂鱼（Ｂｏｌｅｏｐｈｔｈａｌｍｕｓ ｐｅｃｔｉｎｉｒｏｓｔｒｉｓ）暴露于０．０５、０．２０和０．５０ｍｇ／Ｌ不同质量浓度苯并（ａ）芘（ＢａＰ）溶液中１周,其肝脏谷胱甘肽过氧化物酶（ＧＰｘ）活性的变化。结果显示：０．５ｍｇ／Ｌ ＢａＰ组中,随暴露时间的延长,大弹涂鱼肝脏ＧＰｘ活性被显著抑制（Ｐ≤０．０５）;暴露３ｄ,随ＢａＰ浓度的增加,ＧＰｘ活性显著降低（Ｐ≤０．０５）,表明高剂量的ＢａＰ可     

菲在厚壳贻贝体内的富集与释放及其对HSP70 mRNA表达的影响

以厚壳贻贝(Mytilus coruscus)为研究对象,开展不同暴露浓度(4、20和100 µg/L)菲(phenanthrene, PHE)的富集(10 d)和释放(5 d)实验,分别利用高效液相色谱法和荧光定量qPCR法分析了厚壳贻贝内脏团、外套膜、闭壳肌对PHE的富集和释放实验及HSP70 mRNA表达量的变化。结果显示,在10 d的富集阶段,厚壳贻贝3个组织对PHE的富集能力大小表现为内脏团>外套膜>闭壳肌;3个组织对PHE的富集含量随时间的增加而增加,同时,也随暴露浓度的增加而增加;在释放实验阶段,厚壳贻贝3个组织中PHE含量在释放前期迅速下降,但在15 d时,3个组织中PHE残留量仍均高于对照组;PHE对厚壳贻贝体内HSP70 mRNA诱导表达具有组织特异性,其中外套膜中HSP70 mRNA表达量最高。研究结果可为PHE在贝类体内的富集动力学及致毒机制研究提供参考依据。     

苯并（a）芘对大弹涂鱼肝脏DNA的损伤

在实验生态条件, 用碱解旋技术检测了暴露于BaP后大弹涂鱼肝脏的DNA单链断裂程度,结果发现DNA单链断裂程度同时受到曝污时间和曝污浓度的影响,并具有一定的时间－效应和剂量－效应特征;污染解除后DNA单链断裂程度未明显减轻,表明DNA损伤的修复能力较弱。以上这些 结果表明DNA单链断裂适于作为BaP暴露后DNA损伤的检测指标。     

菲和苯并（b）荧蒽曝露对翡翠贻贝外套膜的氧化胁迫及损伤

实验室条件下研究了不同质量浓度（2.0μg.L-1、10.0μg.L-1和50.0μg.L-1）的菲（PHE）和苯并（b）荧蒽（BbF）胁迫15 d和清洁海水恢复7 d中翡翠贻贝（Perna viridis）外套膜组织中超氧化物歧化酶（SOD）活力和丙二醛（MDA）质量摩尔浓度的变化。结果表明,PHE胁迫下翡翠贻贝外套膜SOD活力呈先升高后降低的变化规律;BbF胁迫下的翡翠贻贝外套膜SOD活力在胁迫第15天时被显著诱导（P〈0.05）。从b（MDA）的变化来看,PHE和BbF均可导致翡翠贻贝外套膜明显的氧化损伤,之后在清洁海水的净化过程中,这种损伤逐渐降低并恢复至正常水平。鉴于2种PAHs胁迫下翡翠贻贝外套膜SOD活力和b（MDA）均发生明显变化并表现出一定的差异性,翡翠贻贝体内的生化指标适合指示PAHs对海洋环境的污染。     

缢蛏IGFBP基因结构及生长性状相关SNP筛选

类胰岛素生长因子结合蛋白(IGFBP)是IGF系统的一部分,主要参与IGF的运输、定位和生物活性调节。本研究采用RACE技术和长PCR技术,克隆了缢蛏IGFBP基因的cDNA和DNA全长序列,应用荧光定量PCR技术分析了缢蛏不同发育时期和不同组织中IGFBP mRNA的表达特征,并进一步筛选了IGFBP基因与生长性状相关的SNP位点。序列分析表明,缢蛏IGFBP cDNA序列全长631 bp,包括5'端非编码区60 bp,3'端非编码区136 bp和开放阅读框435 bp,编码144个氨基酸。该基因含有保守的IGFBP-N端,包含12个半胱氨酸残基,其中1～18个氨基酸为信号肽,属于分泌型蛋白。IGFBP DNA全长3 122 bp,其中包含1个内含子(2 687 bp)和2个外显子(200和235 bp)。荧光定量PCR结果显示,IGFBP mRNA在消化腺组织中表达量最高;在缢蛏的稚贝期,IGFBP mRNA呈现高表达,而在其他发育时期表达量低。在IGFBP基因中筛选到4个SNP位点,其中1个SNP位点与缢蛏的壳长和体质量呈显著相关。     

The effects of temperature on the uptake and metabolism of benzo[a]pyrene in isolated gill cells of the gulf toadfish,Opsanus beta

The effects of acclimation temperature and acute temperature change on the uptake and metabolism of the procarcinogen benzo[a]pyrene (BaP) by gill cells of the gulf toadfish, Opsanus beta, were examined. BaP was rapidly accumulated by isolated gill cells and uptake rates were directly proportional to BaP concentration in the medium (1 to 100 μg/ml). Uptake rates were higher in cells isolated from fish acclimated to 18°C when compared to cells from 28°C acclimated fish at all incubation temperatures. When cells were exposed to BaP at the respective acclimation temperatures of the fish, uptake rates were similar (0.14 ± 0.01 at 18°C and 0.12 ± 0.01 μg BaP/s/10 mg cells at 28°C). This finding is discussed in view of results which showed a partial compensation of membrane fluidity in plasma membranes isolated from fish from the two acclimation temperatures. At higher incubation temperatures, cells from fish acclimated to 18°C metabolized BaP at a greater rate than those at 28°C (49.6 ± 1.92 and 43.0 ± 2.24 μg/g/8h, respectively, at 23°C). Low but detectable activities of common biotransformation enzymes (aryl hydrocarbon hydroxylase, glutathione-S-transferase) and cytochrome P-450 content were found, however, no significant differences were evident between cells from fish acclimated to different temperatures. To whom to address correspondence     

缢蛏EGFR基因内含子1内SNP位点多态性与生长性状相关性

为研究缢蛏表皮生长因子受体基因(epidermal growth factor receptor,EGFR)单核苷酸多态性(single nucleotide polymorphism, SNP)与生长性状(壳长、壳宽、壳高和体质量)的相关性。本实验利用直接测序法从缢蛏EGFR基因的第一个内含子序列中共筛选到17个SNP位点。卡方检验结果显示,在17个位点中,有13个位点符合Hardy-Weinberg平衡,位点多态性检测显示17个位点中有10个位点表现为中等多态性(0.25PIC0.5)。利用一般线性模型(general linear model,GLM)及多重比较对缢蛏EGFR基因中17个SNPs的多态性与生长性状(壳长、壳宽、壳高和体质量)进行相关性分析,结果显示,16个SNP位点均与缢蛏的壳长、壳宽、壳高及体质量呈显著性相关。由此可见,EGFR基因可作为缢蛏生长性状改良的候选辅助分子标记,并且为进一步研究其生长相关功能奠定基础。     

近江蛏精子超微形态结构观察及与缢蛏精子的比较

利用扫描电镜和透射电镜分别观察了近江蛏和缢蛏成熟精子的超微形态结构。发现近江蛏精子与缢蛏精子在超微形态结构上差异很大。近江蛏精子为典型的原生型,成熟精子由头部、中段和尾部组成,头部包括顶体和细胞核。近江蛏精子与缢蛏精子顶体均为保龄球状,但近江蛏精子顶体全长比缢蛏短。近江蛏精子细胞核略扁圆形,外缘具8～9个圆弧形凸起;缢蛏精子细胞核则呈圆球状。近江蛏精子中段由线粒体和中心粒复合体构成,线粒体一般5个,个别4～6个;缢蛏线粒体5个或6个。近江蛏精子尾部为细长的鞭毛,轴丝为“9 2”结构,与缢蛏的相同。从近江蛏与缢蛏的精子形态差异看,两者应属于种间差异。     

The toxicokinetics of benzo[a]pyrene in juvenile coho salmon, Oncorhynchus kisutch, during smoltification

The activities of Phase I and Phase II biotransformation enzymes in the livers of yearling coho salmon (Oncorhynchus kisutch), were measured biweekly from February until the release date from the hatchery in mid-June, in order to observe any alterations in baseline levels during smoltification. Peak enzyme activities occurred in February and March and then declined through to June. Total cytochrome P450 levels ranged from 0.024±0.009 to 0.095±0.010 nmol mg^-1 microsomal protein, ethoxyresorufin O-deethylase activity ranged from 2.74±0.75 to 9.94±0.85 pmol min^-1 mg^-1 microsomal protein, and glutathione S-transferase activity ranged from 0.07±0.01 to 0.33±0.01 μmol min^-1 mg^-1 cytosolic protein during this period. Following an intraperitoneal injection of [3H]benzo[a]pyrene (B[a]P), elimination occurred rapidly (>71% excreted into the bile within 24h) from February to June. Although the distribution of B[a]P in tissues changed through the sampling period, the highest leels of B[a]P-derived radioactivity were found in the liver, bile and fat. Analysis of the bile revealed that 55 to 63% of the radioactivity was Phase I metabolites, 16 to 24% glucuronide conjugates, 8% sulfate conjugates, 7% other conjugates and 6% aqueous-soluble metabolites. These findings suggest that the transformation from freshwater adapted coho ‘parr’ to ‘smolts’, can significantly alter biotransformation enzyme activities and the distribution and elimination of xenobiotics such as benzo[a]pyrene in these fish. This revised version was published online in July 2006 with corrections to the Cover Date.     

缢蛏选优群体和全同胞家系早期生长性能的比较

为了比较缢蛏早期的生长性能,以乐清湾的优良群体子四代为亲本材料,分别建立了群体繁育组(QF)、群体选优组(QX)和27个全同胞家系(F1、F2、…F30),其中F18、F24和F28 3个家系由于幼虫死亡率过高而淘汰,全同胞家系建立采用单对配对的方法。对各实验组的受精率、D幼率、变态率、不同阶段的生长速度和规格大小等指标进行了分析。结果发现,各实验组受精率、D幼率、D形幼虫大小和变态率均无显著差异。不同发育阶段各实验组的个体大小、生长速率不同,群体选优组(QX)在幼虫发育的各个时期都显著大于群体繁育组(QF)。全同胞家系间存在着生长差异,其中家系F2、F7、F9、F13、F19壳长显著大于群体繁育组(QF);家系F5、F6、F14、F25、F27壳长显著小于群体繁育组(QF)。通过比较各家系和群体组早期的生长性能,筛选到优良群体和家系资料,为今后缢蛏良种的培育提供了理论基础和优良实践材料。     

缢蛏过氧化氢酶基因的克隆及其功能

过氧化氢酶(catalase, CAT)是抗氧化酶体系的主要成员,在维持机体氧化还原平衡、抵御病原感染过程中具有重要作用。为研究CAT基因在软体动物应答病原胁迫过程中的作用,实验采用RACE技术通过克隆和序列拼接获得了缢蛏CAT基因的全长cDNA序列,并命名为ScCAT。ScCAT基因全长为2 840 bp,编码508个氨基酸。序列分析显示,Sc CAT蛋白含有1个CAT核心结构域(25～410),1个保守的酶活性位点(61FNRERIPERVVHAKGAGA78)和1个亚铁血红素结合位点(351RLFSYPDTH359)。多序列比对和系统进化树分析结果显示,Sc CAT属于CAT基因家族,且与无脊椎动物文蛤的亲缘关系最近。组织分布显示,ScCAT在所有检测的组织中均能表达,其中在肝胰腺中表达量最高,鳃中次之,血细胞中的表达量最低,分别为闭壳肌的85.67倍、50.09倍和0.76倍。在副溶血弧菌胁迫下,ScCAT在缢蛏肝胰腺中的表达明显上升,且在12 h达到最高值,为对照组的3.56倍;酶活性测定结果显示,副溶血弧菌胁迫显著诱导缢蛏肝胰腺和鳃组织中的CAT活性。为进一步探讨Sc CA...     

The effects of temperature on benzo[a]pyrene metabolism and adduct formation in the gulf toadfish,Opsanus beta

In order to examine the effects of temperature on benzo[a]pyrene (BaP) metabolism and adduct formation in the absence of the effects of temperature on uptake, gulf toadfish,Opsanus beta, were given a dose of 0.05 mg/kg³H-BaPvia caudal vein cannulae at their acclimation temperatures. (18 or 28°C) or following an acute temperature change (18 to 28°C or 28 to 18°C). After 72h, BaP-derived radioactivity was detected in all tissues examined and, as in otherin vivo studies of fish, the highest levels were found in the bile, the liver and the kidney. Temperature did not affect the total amount of BaP metabolized and excreted to the bile, but there were significant quantitative differences between temperature treatments in the classes of Phase I metabolites accumulated. Fish acclimated to high temperature accumulated more BaP triols and tetrols (breakdown products of highly carcinogenic BaP diol epoxides) than fish acclimated at low temperature regardless of exposure temperature: the proportion of biliary metabolites as tetrols and triols in each of the four temperature treatments (acclimation: exposure temperature), 28:18, 28:28, 18:18 and 18:28°C were 21.3±3.6, 58.1±6.1, 14.2±1.8 and 20.9±3.2% (mean±SEM, n=4), respectively. Significant quantities of BaP-DNA and BaP-hemoglobin adducts were detected; however, only the amounts of BaP-DNA adducts showed sensitivity to temperature. As predicted from our metabolite data, high acclimation or exposure temperature led to a significant increase in the amount of BaP-DNA adducts formed: adduct formation in the temperature treatments, 28:18, 28:28, 18:18 and 18:28°C were 342±52, 526±51, 155±42 and 252±55 fg BaP/ µg DNA (mean±SEM, n=4), respectively. These results are discussed in the context of mechanisms of high temperature-enhancement of carcinogenesis in fish.     

缢蛏动态能量收支生长模型的建立

为建立缢蛏动态能量收支(dynamic energy budget,DEB)的数值模型,实验根据DEB理论,采用相应方法测定计算了建模必须的形状系数(δm)、阿伦纽斯温度(TA)、单位时间单位体积维持生命所需的能量[pM]、形成单位体积结构物质所需的能量[EG]和单位体积最大储存能量[EM]等基本参数.以水温和叶绿素浓...     

不同月龄缢蛏新品种数量性状的相关与通径分析

为了检测缢蛏新品种"申浙1号"不同月龄数量性状间的相关性。随机选取4、9、11月龄缢蛏个体60个以上,测量其壳长(SL)、壳高(SH)、壳宽(SW)、活体质量(W),采用相关与通径分析方法分析壳形态性状对活体质量的作用效果。结果显示,各数量性状之间的相关关系均达到极显著水平,其中与4、11月龄质量相关系数最大的是壳长,分别为0.911、0.631,与9月龄活体质量相关系数最大的是壳高,为0.653。通径分析结果显示,对4、9、11月龄活体质量的直接影响最大的分别是壳长(0.562)、壳宽(0.433)、壳高(0.394),决定系数与以上通径分析结果的变化趋势一致。利用逐步回归的方法分别建立4、9、11月龄缢蛏活体质量(W)的最优回归方程:W4=–0.756+0.039SL+0.112SW,R2=0.849;W9=–10.622+0.095SL+0.404SH+0.644SW,R2=0.631;W11=–23.772+0.207SL+0.805SH+0.587SW,R2=0.909。研究结果为缢蛏人工选育过程中的亲贝选择和产量预测等提供了基础数据。