热胁迫对多化性家蚕5龄雌性幼虫脂肪体谷胱甘肽氧化还原循环的影响  

Impact of Heat Shock on Glutathione Redox Cycle in Fat Body of Female Larvae of Polyvoltine Silkworm(Bombyx mori) During the Fifth Instar

作　　者：朱文娟[1] 袁燕萍[1] 司马杨虎[1] 赵林川[1] 

机构地区：[1]苏州大学基础医学与生物科学学院,江苏苏州215123

出　　处：《蚕业科学》2015年第6期1029-1035,共7页ACTA SERICOLOGICA SINICA

基　　金：家蚕基因组生物学国家重点实验室开放课题(No.20120-009)

摘　　要：谷胱甘肽氧化还原循环对保障机体的内环境稳定至关重要。对多化性家蚕品种兰溪10的5龄雌性幼虫连续72 h分别以常温25℃和32℃热胁迫处理,测定脂肪体中与谷胱甘肽氧化还原循环相关分子的含量和酶活性变化。在常温和热胁迫处理的雌蚕脂肪体中均检测不到谷胱甘肽过氧化物酶(GPX)活性。与常温处理组相比,热胁迫处理组的雌蚕脂肪体中还原型谷胱甘肽(GSH)含量、GSH/氧化型谷胱甘肽(GSSG)比值、谷胱甘肽S-转移酶(GST)活性和硫氧还蛋白还原酶(TrxR)活性均显著降低,H2O2、GSSG、总谷胱甘肽的含量以及硫氧还蛋白过氧化物酶(TPX)活性和TPX编码基因Bmprx的转录水平显著提高,谷胱甘肽还原酶(GR)活性和TPX的另一个编码基因Bmtpx的转录水平则无显著差异。研究结果表明,在热胁迫环境下家蚕脂肪体中的Bmprx基因被诱导上调表达,使TPX活性提高和TrxR活性降低,导致GSH/GSSG比值显著降低,谷胱甘肽氧化还原循环向氧化态转移。Glutathione redox cycle is crucial to maintain the stability of internal environment in organisms. The female lar- vae of polyvoltine silkworm （Bombyx moil） variety Lanxi 10 were treated under normal temperature （25℃） and high temperature （32 ~C） for 72 h respectively, and then the variations of molecule contents and enzymatic activities related to glutathione redox cycle in fat body were determined. Activity of glutathione peroxidase （GPX） could not be detected in fat body of female larvae treated at 25℃ and 32℃. Compared with normal temperature treatment, the content of reduced glutathione （GSH）, GSH/oxidized glutathione （GSSG） ratio, glutathione S-transferase （GST） activity and thiore- doxin reductase （TrxR） activity were significantly decreased in fat body of female larvae after heat stress. The contents of H202, GSSG and total glutathione, thioredoxin peroxidase （TPX） activity, and the transcriptional level of TPX encoding gene Bmprx were significantly increased. And there was no significant difference of glutathione reductase （GR） and transcriptional level of TPX encoding gene Bmtpx, respectively. These results indicated that the decline of GSH/GSSG ratio and transfer of glutathione redox cycle to oxidative conditions in fat body of silkworm larvae under heat stress were due to the increase of TPX activity and the decline of TrxR activity through the up-regulated transcription of Bmprx gene.

关 键 词：家蚕 脂肪体 谷胱甘肽氧化还原循环 硫氧还蛋白过氧化物酶 硫氧还蛋白还原酶 热胁迫 

分 类 号：S881.2[农业科学—特种经济动物饲养]