饲料添加剂硒和谷胱甘肽对微囊藻毒素胁迫下罗非鱼肝脏去毒相关基因诱导表达的影响  

Transcriptional responses of detoxification-related genes to dietary Se and glutathione under the stress of microcystins-LR in tilapias

作　　者：王琳[1] 梁旭方[1] 陈晓艳[1] 李光照[1] 刘秀霞[1] 胡永乐[1] 姚煜[1] 

机构地区：[1]暨南大学生物工程学系,广东广州510632

出　　处：《暨南大学学报（自然科学与医学版）》2010年第1期95-99,共5页Journal of Jinan University(Natural Science & Medicine Edition)

基　　金：国家科技部863项目(2007AA09Z437);国家科技部973项目(2009CB118702);国家自然科学基金项目(30670367);广东省自然科学基金项目(031886);广东省科技计划项目(2007B020701002)

摘　　要：为从分子水平探讨饲料添加剂硒(Se)和谷胱甘肽(GSH)对淡水养殖鱼类肝脏微囊藻毒素胁迫下去毒分子机理的影响,实验杂交罗非鱼一组喂食含0.15 mg/kg Se的富硒酵母粉饲料,一组喂食含普通酵母粉的饲料,喂食一个月以上;实验尼罗罗非鱼一组喂食含1 g/kg GSH的饲料,一组喂食普通饲料,两组均饱食10 d.所有实验组再均分两组,一组腹腔注射磷酸缓冲液(PBS),一组按体质量注射腹腔注射50μg/kg微囊藻毒素-LR(MC-LR),24 h后分离肝脏组织.以β-肌动蛋白作为外参照,采用半定量RT-PCR方法研究Se和GSH分别对罗非鱼肝脏去毒相关基因转录水平的诱导改变.结果表明,未喂食Se的实验组,杂交罗非鱼肝脏alpho-可溶性谷胱甘肽S-转移酶(sGSTA)和谷胱甘肽过氧化物酶(GPX)基因mRNA表达水平在腹腔注射50μg/kg MC-LR 24 h后,均较PBS组有诱导趋势;Se+MC-LR组sGSTA和GPX基因mRNA表达水平,均较Se+PBS组略低,可能与添加剂的低剂量添加相关.喂食GSH的实验组,尼罗罗非鱼腹腔注射MC-LR组,肝脏sGSTA基因mRNA表达水平较PBS组有诱导趋势;Se+MC-LR组GPX基因mRNA表达水平,较Se+PBS组有升高趋势,而sGSTA和rho-可溶性谷胱甘肽S-转移酶(sGSTR)基因mRNA表达水平则轻微降低.本实验首次从基因表达水平比较研究了Se和GSH对罗非鱼微囊藻毒素压力情况下,肝脏去毒酶基因表达的影响变化,为Se和GSH饲料添加剂在鱼类饲料中的合理添加提供分子水平的理论依据.To study the transcriptional responses of detoxification-related liver genes to dietary Se and glutathione （GSH） , the O. niloticus x O. aureus and O. niloticus were separated into two groups, respectively. One group O. niloticus x O. aureus was fed the diet （ additive Se 0. 15 mg/kg feed） and the other group was fed control diet for one month; One group O. niloticus was fed the diet （additive GSH 1 g/kg feed） and the other group was fed control diet for 10 d. Half of every group was exposed to a single 50 ug/kg body weight dose of pure MC-LR by intraperitoneal injection, and were then sacrificed at 24 h post-exposure. The control treatments were intraperitoneal injection PBS. Using β-ACT as external control, the relative liver alpha- and rho- class soluble glutathione S-transferase （sGSTA, sGSTR） and glu- tathione peroxidase （GPX） were determined by semi-quantitative PCR within the exponential phase. The results indicated the levels of sGSTA and GPX mRNA of O. niloticus × O. aureus MC-LR treatment were higher that the PBS treatment; the levels of sGSTA and GPX mRNA of O. niloticus × O. aureus Se ＋ MC- LR treatment were lower than Se ＋ PBS treatment. The levels of sGSTA mRNA of O. niloticus was induced in MC-LR treatment than PBS treatment; the levels of GPX mRNA in Se ＋ MC-LR was higher than Se ＋ PBS treatment, however the levels of sGSTA and sGSTR were decrease. This study provides abundant evidences to develop new dietary additives to stimulate detoxification-related genes expression levels in aquaculture.

关 键 词：硒 谷胱甘肽 微囊藻毒素 活体诱导表达 可溶性谷胱甘肽S-转移酶 谷胱甘肽过氧化物酶 罗非鱼 

分 类 号：Q786[生物学—分子生物学]