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1.
采用组织学和分子生物学方法,研究了投喂芳香化酶抑制剂来曲唑(LE)后暗纹东方鲀(Takifugu obscures)初孵仔鱼CYP19A、DMRT1基因表达以及性腺的组织学变化,以期进一步了解P450芳香化酶(P450arom)在鱼类早期性别分化过程中的作用。RT-PCR结果显示,对照组样品CYP19A和DMRT1表达显示性二态,雌性表达CYP19A基因,雄性表达DMRT1基因。LE处理组在性别分化期间,雄性样品单一表达DMRT1,雌性样品则同时表达CYP19A和DMRT1。qRT-PCR结果显示:LE处理组雌性仔鱼CYP19A基因表达被显著抑;虽然在仔鱼出膜后22d(dph)的表达水平高于9 dph,但仅为同日对照组的2.11%。LE处理组雌性样品22 dph时DMRT1基因表达量上调,至150 dph时达对照组雄性水平。55 dph的性腺组织学结果表明,LE处理可导致暗纹东方鲀稚鱼原始卵巢退化,并向功能性精巢发育。150 dph的LE处理组性腺均为精巢,并与对照组精巢发育同步。结论认为,暗纹东方鲀性腺分化期间P450arom是卵巢形成和维持发育所必须的,抑制P450arom活性可导致雌性暗纹东方鲀发生雄性化逆转。  相似文献   

2.
以花鲈(Lateolabrax maculatus) 1~214 dph (day post hatching)的仔稚鱼、幼鱼以及18月龄的雌鱼和雄鱼为研究对象,研究了花鲈早期性腺发生、发育和分化情况;分析了性腺分化过程中性别相关基因(cyp11b和cyp19a1a)的表达及与性别之间的关系。结果显示,在30 dph [全长为(1.28± 0.10) cm],首次在中肾管前端的腹腔膜周围观察到原始生殖细胞(primordial germ cells, PGCs),说明30 dph前是花鲈胚后PGCs迁移至生殖嵴的关键时期;在55 dph [全长为(2.45±0.19) cm],观察到一对呈对称分布的原始性腺已经形成,说明花鲈幼鱼的原始性腺在30~55 dph (全长为1.28~2.45 cm)之间发生;55~180 dph时(全长为2.45~12.28 cm),原始性腺不断发育变大,并且一直处于未分化状态;180 dph后性腺开始分化;在195 dph [全长(14.54±1.54) cm]观察到精巢开始分化,卵巢于205 dph [全长为(15.86±0.94) cm]开始分化,且性腺的解剖学分化要早于细胞学分化;18月龄的花鲈幼鱼性腺发育到Ⅱ期。性别分化相关基因cyp19a1a在花鲈卵巢中的表达量高于同期精巢,说明其在卵巢的分化及维持中发挥更关键的作用,而cyp11b在18月龄幼鱼Ⅱ期精巢中的表达量显著高于同时期的卵巢及Ⅰ期精巢,说明其主要在精巢的分化及维持中扮演重要角色。本研究结果不仅可以丰富花鲈的繁殖生理学资料,也为其性别调控技术的研究提供了科学依据。  相似文献   

3.
在水温21~23℃,pH 8.2~8.5,溶解氧6.00~7.50mg/L的条件下,采用半静水法研究了非离子氨氮和亚硝酸盐氮对全长(1.6±0.2)cm、体质量为(0.11±0.05)g的暗纹东方鲀稚鱼的急性毒性效应。试验结果表明,暗纹东方鲀稚鱼受到非离子氨氮和亚硝酸盐氮胁迫后,先后出现鱼体体色变白、扭曲、侧游、失去平衡、昏迷等中毒症状。随着非离子氨氮和亚硝酸盐氮质量浓度的提高和胁迫时间的延长,暗纹东方鲀稚鱼死亡率逐渐升高,存在明显的剂量效应和时间效应关系。非离子氨氮和亚硝酸盐氮对暗纹东方鲀稚鱼96h半致死质量浓度分别为0.46mg/L(95%置信限0.34~0.64mg/L)和290.12mg/L(95%置信限255.16~329.87mg/L),安全质量浓度分别为0.046 mg/L和29.01mg/L。非离子氨氮和亚硝酸盐氮对暗纹东方鲀稚鱼具有一定毒性,且非离子氨氮毒性大于亚硝酸盐氮毒性。  相似文献   

4.
为探究暗纹东方鲀(Takifugu obscures)抗苗勒氏管激素Ⅱ型受体(anti-Müllerian hormone receptorⅡ,Amhr2)基因的序列和结构信息,初步研究amhr2基因在性腺发育和性别分化过程中的作用,实验通过设计简并引物扩增及RACE技术,克隆出暗纹东方鲀amhr2完整的CDS区,分析其相应的生物信息学特征及其在不同组织和不同发育期的mRNA表达水平。结果表明:amhr2序列cDNA全长为1 868 bp(NCBI登录号:MH218814),编码513个氨基酸,与红鳍东方鲀(Takifugu rubripes)同源性最高,达99%。氨基酸多重序列比对结果显示,Amhr2氨基酸序列中的近C-末端区域序列较为保守;通过构建系统进化树发现,暗纹东方鲀Amhr2与红鳍东方鲀亲缘关系最近。荧光定量PCR分析显示,暗纹东方鲀amhr2仅在性腺中表达,且卵巢中的表达量明显高于精巢;并且在性腺早期发育过程中,amhr2在精巢和卵巢中的表达量均呈现出先降低再迅速升高的表达趋势。研究结果表明,amhr2在暗纹东方鲀中的表达具有组织特异性,且在性别分化和性别维持等过程中发挥重要的作用。  相似文献   

5.
为查明性别分化相关基因在红鳍东方鲀性别分化关键时期的表达规律,以孵化后40、60、80 d的红鳍东方鲀幼鱼为试验对象,对性腺进行组织学观察,并对采样个体进行遗传性别鉴定,采用实时荧光定量PCR(qRT-PCR)的方法研究amhr2、dmrt1、gsdf、cyp19a1a、foxl2、dnmt1基因在遗传型为XX(雌性)...  相似文献   

6.
性腺型芳香化酶基因是一种调节雌雄激素平衡的基因。为初步探究暗纹东方鲀性腺型芳香化酶基因在性腺发育和性别分化过程中的作用,通过RACE及荧光定量PCR技术,成功克隆出暗纹东方鲀性腺型芳香化酶基因的cDNA全长序列,共1786 bp,编码514个氨基酸,与红鳍东方鲀及星点东方鲀同源性最高。氨基酸序列分析显示,该基因编码的蛋白是一种稳定的亲水性蛋白,但不存在信号肽序列;性腺型芳香化酶含有38个磷酸化位点、4个N-糖基化位点、2个跨膜保守结构域;其氨基酸序列在哺乳动物和鱼类中均十分保守,且含有跨膜区、Ⅰ-螺旋区、Ozol′s肽区、芳香化酶特异性保守区和亚铁血红素结合区等功能保守区。表达分析显示,暗纹东方鲀性腺型芳香化酶基因主要在肌肉和卵巢中表达,其次在其他组织中也有少量表达,而且在幼鱼不同发育期卵巢中的表达量呈现出逐渐升高再降低的表达趋势,在精巢中则基本不表达。研究结果表明,性腺型芳香化酶基因很可能参与了暗纹东方鲀雌鱼性腺分化后卵巢的发育、雌性特征的维持和其他组织的发育等过程。  相似文献   

7.
MS-222和丁香酚对暗纹东方鲀幼鱼麻醉效果的比较研究   总被引:1,自引:0,他引:1  
为研究MS-222和丁香酚对暗纹东方鲀(Takifugu obscurus)幼鱼的麻醉效果,选择体质量为(71.37±3.24)g的幼鱼进行实验。根据暗纹东方鲀幼鱼麻醉和复苏时的主要行为特征,将麻醉过程分为6期,复苏过程分为4期。结果显示:随着两种麻醉剂浓度的升高,幼鱼的麻醉时间逐渐缩短,复苏时间逐渐延长;MS-222和丁香酚分别在浓度60 mg·L~(-1)和30 mg·L~(-1)时,幼鱼的最终麻醉程度达到麻醉6期(延髓麻醉期);MS-222浓度在120~140 mg·L~(-1)、丁香酚浓度在60~70 mg·L~(-1)时,幼鱼均可在3 min内麻醉、5 min内复苏;随着水温的上升,幼鱼的麻醉时间和复苏时间均呈现缩短的趋势。幼鱼进入麻醉6期后,随着暴露在空气中时间的增加,MS-222处理组幼鱼的复苏时间先缩短后延长,暴露25 min时复苏时间已超过对照组(未暴露),此后复苏时间明显增加,幼鱼成活率为100%;丁香酚处理组幼鱼复苏时间随暴露时间延长持续上升,暴露6 min后复苏时间上升趋势加快,暴露15 min之前幼鱼成活率为100%,暴露20 min时幼鱼成活率降低到80%。研究表明,120~140 mg·L~(-1)的MS-222和60~70 mg·L~(-1)的丁香酚均对暗纹东方鲀幼鱼有良好的麻醉效果,具有麻醉时间短、复苏快的特点,两者均可作为暗纹东方鲀幼鱼的理想麻醉剂。  相似文献   

8.
通过 96 h 急性毒性实验研究水体铜暴露对暗纹东方鲀(Takifugu fasciatus)生理生化及脂代谢相关基因表达的影响。实验设置对照组、0.1 mg/L 和 0.2 mg/L (96-h LC50) 3 个铜处理组。结果表明,铜在暗纹东方鲀肝、肌肉和全鱼中的积累量随着处理浓度的提高而提高。同等浓度处理下,铜的积累量为肝脏>全鱼>肌肉。随着铜处理浓度的提高,肝脏中丙二醛(MDA)含量及抗氧化酶活性[谷胱甘肽过氧化物酶(GSH-PX),总超氧化物歧化酶(SOD)和过氧化氢酶(CAT)]显著上升。急性铜暴露诱发肝脏血细胞沉积以及血窦扩张的症状。在鳃中,诱发上皮细胞增生,顶部棒状以及产生动脉瘤等症状。急性铜胁迫后,暗纹东方鲀肠道中的淀粉酶活性显著上升,但脂肪酶活性显著下降。在肝脏中,随着处理浓度的提高,淀粉酶、蛋白酶和脂肪酶活性显著降低。在 0.1 mg/L 处理组,脂肪合成相关基因(G6PD、6PGD、LPL、Fas 和 Acc)的表达量最高。但在 0.2 mg/L 处理组中,脂肪分解相关基因(HSL 和 CPT 1)的表达最高。急性铜胁迫后对转运因子 PPARα的影响不显著,但转运因子 PPAR γ的表达量显著上升。本实验表明铜对暗纹东方鲀生理生化指标及脂代谢相关基因的表达均产生显著影响,本研究为暗纹东方鲀养殖过程中铜的合理使用提供有益的指导价值,也为生产中更好地监控重金属污染提供一定的技术指标参考。  相似文献   

9.
为探究sox9基因在大黄鱼性别决定与分化过程中的作用,利用RACE方法克隆得到大黄鱼sox9a和sox9b 2个基因,采用实时荧光定量PCR (qRT-PCR)分析其在雌雄个体不同组织和不同发育阶段的表达规律,并检测了其在17β-雌二醇处理后的遗传雄性和17α-甲基睾酮诱导处理后遗传雌性幼鱼中的表达变化。结果显示,大黄鱼sox9a c DNA全长2 442 bp(NCBI登录号:MH996431),包含476 bp 5′UTR、466 bp 3′UTR、1 500 bp ORF,编码499个氨基酸。大黄鱼sox9b cDNA全长为2 199 bp (NCBI登录号:MH996432),包含335 bp5′UTR、415 bp 3′UTR、1 449 bp ORF,编码482个氨基酸。qRT-PCR分析显示,sox9a基因主要在性腺、眼、脑、肝脏中表达,精巢中的表达量显著高于卵巢;sox9b在大黄鱼各组织中广泛表达,但以精巢中表达量最高,而卵巢中只有痕量表达。在鱼苗性腺发育初期,sox9a/b的表达量都维持在较低水平;随着鱼苗长大,sox9a/b的表达量在84 dph、123 dph 2次达到高峰,随后开始下降,10 mph后又逐渐上升。17β-雌二醇处理能够显著下调遗传雄性大黄鱼sox9a和sox9b基因在性腺中的表达,17α-甲基睾酮处理则显著上调遗传雌性大黄鱼sox9a和sox9b基因在性腺中的表达。研究表明,sox9a/b基因与大黄鱼性别发育和分化过程密切相关,对大黄鱼精巢的发育与维持起重要的调控作用,而且两个基因的功能可能具有一定程度的分化。  相似文献   

10.
甘为  方展强 《水产学报》2016,40(10):1542-1555
硬骨鱼类CYP19基因与生物的性别分化和激素调节相关,因此可开发用来探究环境激素污染与基因表达的关系。本研究首次克隆和分析了食蚊鱼CYP19a cDNA的全系列,为将CYP19基因作为监测环境激素生物标志物的研究提供了全面的实验数据。根据CYP19a基因c DNA保守区域设计引物,扩增保守区域并测序。采用RACE法扩增食蚊鱼CYP19a基因c DNA序列全长,对其蛋白序列进行同源性分析,并将序列应用于CYP19a mRNA转录水平的RT-PCR法检测中。成功克隆食蚊鱼CYP19a基因全长,获得CYP19a基因总长为2020 bp,ORF为238~1791 bp,共编码518个氨基酸,对其编码的蛋白质进行有关信号肽、跨膜螺旋、亲水性/疏水性、一级结构、二级结构和三级结构分析,与其他硬骨鱼类底鰆、青鰆、平鲷、鲫、鲤和斑马鱼的性腺CYP19a基因作同源性比较,其基因相似度分别为93%、84%、84%、71%、71%和66%。用MEGA6.0软件对19个物种的CYP19a基因进行聚类分析,食蚊鱼CYP19a基因与底鰆、青鰆同源性最高,说明芳香化酶在进化上相对保守。确定从食蚊鱼性腺所克隆的CYP19a基因是芳香化酶基因,证明食蚊鱼的芳香化酶是由CYP19a和CYP19b两种基因编码的。食蚊鱼卵巢芳香化酶具有3个高度保守的片段,并具有催化活性。  相似文献   

11.
向性成熟的泥鳅(Misgurnus anguillicaudatus)和大鳞副泥鳅(Paramisgurnus dabryanus)个体注射绒毛膜促性腺激素,对所获得的卵子和精子进行人工授精。把胚胎分别置于20℃、25℃和30℃条件下,使其发育。经性腺检查发现,随着温度的升高两种泥鳅中雄性个体所占的比例明显升高,获得明显的偏雄比率群体。根据已知细胞色素P450芳香化酶CYP19α基因序列设计嵌套简并引物用巢式PCR扩增并克隆出了两种泥鳅的CYP19α的DNA片段。泥鳅CYP19α片段和大鳞副泥鳅CYP19α片段分别长941bp和935bp。在此基础上用各自的特异引物克隆出两种泥鳅CYP19α的相应CDNA片段。通过基因组DNA和cDNA序列的比较证明两种泥鳅的CYP19α基因均包含2个内含子和3个外显子,编码的蛋白质序列长84氨基酸残基。以GAPDH基因为对照,分别对2种泥鳅成体组织和不同发育阶段胚胎的CYP19α进行了半定量RT-PCR表达分析,结果表明,二者在成体组织中具有大致相似的表达模式,在卵巢和脑组织中表达量较大,在精巢和肝组织中微量表达,在胚胎中二者的表达模式差异较大。  相似文献   

12.
CYP19 is considered as an important factor affecting reproductive endocrinology in many fishes, and plays an important role in ovarian development, reproductive function and sexual differentiation. In this study, three single nucleotide polymorphisms (SNPs) within CDS of the CYP19a gene were tested and the associations between their genotypes and four reproductive traits were analyzed in 65 Japanese flounder individuals with Polymerase chain reaction and Single-stranded conformational polymorphism (PCR–SSCP). Results indicated that a SNP in the exon7 of CYP19a gene, SNP2, was significantly associated with 17β-estradiol (E2) (P < 0.05) and gonadosomatic index (GSI) (P < 0.05). Individuals with genotype AB of SNP2 had significantly higher serum E2 levels (P < 0.05) and GSI (P < 0.05) than those of genotype AA or BB. In addition, there was significant association between one diplotype based on three SNPs and reproductive trait. The genetic effects for both serum E2 of diplotype D9 and GSI of diplotype D1 were respectively much higher than those of other diplotypes (P < 0.05). The evidence of the associations between genetic variants with serum E2 and GSI may help explain effects of CYP19a gene in reproductive endocrinology of Japanese flounder.  相似文献   

13.
对斜带石斑鱼(Epinephelus coioides)卵巢进行组织学分析,根据卵母细胞的发育阶段将卵巢发育划分为7个时期(I-VII),检测斜带石斑鱼不同发育时期卵巢中两种促性腺激素受体(gonadotropin receptors,GtHRs),即卵泡刺激素受体(follicle-stimulating hormone receptor,FSHR)和促黄体素受体(luteinizing hormone receptor,LHR)的mRNA水平,同步分析下游卵巢型芳香化酶基因(Cyp19a)的表达模式。实时荧光定量PCR(Real-time PCR)结果显示,FSHR的mRNA水平在I、II时期的卵巢中较低,在III时期开始上调,在IV、V时期显著升高,在VI时期显著下降。相比之下,LHR的转录水平在卵巢发育早期(I-IV)表达较低,在V时期开始有所升高,在VI时期达到峰值。卵巢内Cyp19a的mRNA在I III时期保持较低水平,在IV、V时期的表达显著增强,在VI时期表达明显减弱。在卵巢发育过程中,Cyp19a的整体表达模式与FSHR较为相似。上述结果表明,斜带石斑鱼FSHR和LHR均参与了卵巢发育的调控,但在不同发育时期功能不同。在卵巢发育过程中,FSHR可能是介导Cyp19a正调控的主要因子。本研究旨为阐明斜带石斑鱼GtH/GtHR信号系统在生殖调控过程中的作用提供基础依据。  相似文献   

14.
唐江芳  郑曙明 《水利渔业》2007,27(3):105-107
试验研究了五倍子、复方抗菌剂对鲫鱼CYP3A酶活性的影响。设计复方抗菌剂浓度分别为30mg/kg、10 mg/kg和五倍子浓度为30 mg/kg,采用灌肠给药对鲫鱼进行处理;在试验的第3、7、10天取样测定其肝和肾组织中CYP3A的酶活性变化。结果表明:复方抗菌剂30 mg/kg处理组和五倍子30 mg/kg处理组的肝CYP3A活性较对照组显著降低(P<0.05),且在处理第10天,肝CYP3A酶活性较前2次的降低极显著(P<0.01);而复方抗菌剂10 mg/kg组的肝CYP3A酶活性无显著变化。对于肾组织,各药物组的CYP3A酶活性均无明显变化。  相似文献   

15.
黄芩苷对牙鲆肝CYP1A酶活性及基因表达的影响   总被引:1,自引:1,他引:0  
韩华  李健  李吉涛  张喆 《中国水产科学》2010,17(5):1121-1127
本研究以中药黄芩苷为受试药物,研究其在不同剂量和作用时间下对牙鲆(Paralichthys olivaceus)肝CYP1A酶活性和基因表达的影响。采用体内实验,将黄芩苷按低(50mg/kg·d)、中(100mg/kg·d)、高(200mg/kg·d)3个剂量分别口灌牙鲆,连续给药,并分别于给药3d、6d、9d后取样,测定CYP1A酶活性。结果表明,较空白组而言,给药3d,黄芩苷各剂量组鱼肝中EROD酶(CYP1A标志酶)活性没有明显变化(P0.05);给药6d,高剂量组的EROD酶活性极显著增加(P0.01),中剂量组的则显著增加(P0.05);给药9d,高、中剂量组的EROD酶活性均极显著增加(P0.01),低剂量组的EROD酶活性显著增加(P0.05),且黄芩苷对该酶的诱导作用与剂量和药物作用时间均呈正相关。半定量RT-PCR结果表明,各药物剂量组的CYP1A基因表达水平都发生了上调,且这种表达上调的幅度同CYP1A酶的活性一样,随给药时间和剂量的增加而加强,提示黄芩苷作为诱导剂对CYP1A酶活性的作用机制可能与调控CYP1A的转录水平有关。  相似文献   

16.
17.
Cytochrome P450 aromatase, which is encoded by the CYP19a gene, converts androgens to estradiol. Considerable evidence suggests that estrogens play an important role in fish reproductive process. Therefore CYP19a is an excellent candidate gene for reproductive traits. Variants in the promoter of the CYP19a gene might also be involved in the control of aromatase expression and affect regulatory mechanism linking cholesterol metabolism to the synthesis of sex steroids. In this study, nine single-nucleotide polymorphisms (SNPs) were detected with polymerase chain reaction-single stranded conformational polymorphism (PCR-SSCP), namely A-680G, G-672A, AGTAGT-649 inserting or deleting, T-623C, C-410A, T7-454A, T-402C, TTTCCAGACTGA-345 inserting or deleting, and G-297C. Nine SNPs within the promoter of the CYP19a gene were tested for association with four reproductive traits [serum testosterone (T), serum 17β-estradiol (E2), hepatosomatic index (HSI), and gonadosomatic index (GSI)] in a population of 50 female Japanese flounder individuals. A locus, P3 (TTTCCAGACTGA-345 inserting or deleting, G-297C), was significantly associated with 17β-estradiol (E2) level (P < 0.05) in female Japanese flounder. In addition, there was significant association between one diplotype based on nine SNPs and reproductive trait. The genetic effect for E2 level of diplotype D3 was significantly higher than those of other diplotypes (P < 0.05). Results indicate that these genetic effects of those variants on E2 level may help to explain CYP19a gene status in the reproductive endocrinology of Japanese flounder.  相似文献   

18.
Channel catfish (Ictalurus punctatus) have been previously shown to express two major cytochrome P450 (CYP) protein bands that are cross-reactive with anti-CYP2K1 (rainbow trout, Oncorhynchus mykiss) antibodies on Western blots. These proteins appear to be the major constitutive CYPs in channel catfish and show distinct sex- and age-specific variations in expression. Because I. punctatus is an important agricultural and ecological commodity, and because it displays a high degree of resistance to the toxic effects of many pesticides, the molecular and catalytic characteristics of its biotransformation systems are of interest to those in areas of environmental science and aquaculture research. Using a chromatographic method similar to that employed in the purification of other fish CYP2 enzymes, a single CYP2-related protein (CM-HA3) was isolated from channel catfish hepatic microsomes. The isolated protein displays a relative molecular mass of approximately 47 kDa, and a CO-reduced difference spectrum max of 449.6 nm. The sequence of 15 residues at the amino-terminal of CM-HA3 is 27% identical to both CYP2K1 and CYP2M1 isoforms of rainbow trout. Correlational analysis was employed to characterize potential substrates for this isoform, but no significant relationship was observed with E2 hydroxylation, testosterone hydroxylation, or 7-ethoxycoumarin O-deethylase activities. These data indicate that CM-HA3 is a CYP2 family protein, with as yet uncharacterized substrate specificities.  相似文献   

19.
Streptococcosis, a bacterial disease for multiple fish species, especially tilapia, caused more disruption to the fish culture industry. However, the underlying mechanisms for the occurrence of streptococcosis remain unclear. The aim of this study was to study the effects of streptococcus on the liver of tilapia. In this study, tilapia were injected streptococcal solution (0.05 ml/10 g body weight) and collected blood and liver at 4, 8, 24, 48, 72, 96, 120 and 144 hr after injection. The results showed that the activities of glutamate oxalate transaminase (GOT), glutamate pyruvate transaminase (GPT), alkaline phosphatase (AKP) and superoxide dismutase (SOD) in the serum of tilapia exhibited irregular changes: increase at first, then decrease and increase again. The levels of total antioxidant capacity (T‐AOC), glutathione (GSH) and malondialdehyde (MDA) showed a decreasing tendency in serum after injection, except GSH at 4 hr. The activity of catalase (CAT) decreased in serum at 4, 24, 120 and 144 hr after injection of streptococcal solution, while the content TP enhanced in serum at 48, 72 and 120 hr after injection. Observations of pathological sections showed obvious damage to the liver tissue structure in response to streptococcal infection. Western blotting revealed an increase in ikkbeta (Ikkβ) protein with prolonged infection time and a decrease in NF‐kappa‐B inhibitor alpha (IkB‐α) and ikappab kinase alpha (Ikkα) proteins. The gene expression of cytochrome P4501A (CYP1A) was downregulated in liver at 24 and 48 after injection, while the mRNA levels of heat stress protein 70 (HSP70) and tumour necrosis factor alpha (TNF‐α) increased at 48 and/or 72 hr. Taken together, our findings confirmed that streptococcus can cause serious damage to the liver of tilapia.  相似文献   

20.
In the present study biotransformation and detoxification responses to acute exposure to the polycyclic aromatic hydrocarbons benzo[a]pyrene (B[a]P) were investigated in the liver of Sparus aurata (sea bream). Sexually immature gilthead sea bream were treated by intraperitoneal injection of B[a]P (20 mg kg−1) for 6, 12, 24, and 48 h. B[a]P accumulation was quantified in sea bream liver by mean of gas phase chromatography (GPC-MS) after the various exposure periods. The following biological responses were measured: (1) ethoxyresorufin-O-deethylase (EROD) activity, as a phase I biotransformation parameter; (2) liver glutathione S-transferase (GST) activity as a phase II conjugation enzyme. DNA damage was assessed over time using the single-cell gel electrophoresis comet assay. B[a]P bioaccumulation in the liver resulted in a biphasic curve with an increasing uptake up to 5.55 ± 0.67 μg g−1 dry weight after only 6 h exposure and 4.67 ± 0.68 μg g−1 dry weight after 48 h exposure. EROD activity showed a nonsymmetrical bell-shaped kinetic with a maximum at 24 h and lower but significant activities at 12 and 48 h with respect to control animals. Hepatic GST activities were only significant after 48 h exposure. Comet assay showed an increase in liver cells DNA damage with a maximum after 48 h exposure reaching up to 12.17 %DNA in the tail.  相似文献   

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