家蝇MdSOD3基因的鉴定及其在抵抗重金属胁迫中的作用  

Identification of the gene MdSOD3 and its role in resisting heavy metal stress in housefly(Musca domestica)

作　　者：唐婷[1] 高一夫[1] 刘艳娟[1] 葛旭东[1] 李响[1] 柳峰松[1] 

机构地区：[1]河北大学生命科学学院,河北保定071002

出　　处：《昆虫学报》2012年第3期267-275,共9页Acta Entomologica Sinica

基　　金：河北大学自然科学基金项目(2011211);国家自然科学基金项目(31101669)

摘　　要：超氧化物歧化酶(SOD)是一种重要的抗氧化酶,在昆虫抗氧化保护过程中起着重要作用。本研究通过RT-PCR技术鉴定了家蝇Musca domestica MdSOD3基因(GenBank登录号为JQ408979),cDNA序列817bp,开放阅读框534bp,推导的多肽序列含有177个氨基酸。同源性分析及NJ法系统分析表明MdSOD3与其他物种的Cu/ZnSOD关系较近。荧光定量PCR检测该基因在家蝇幼虫脂肪体、肠、表皮和血细胞中不存在差异表达;在受到不同浓度重金属Cd2+刺激时,MdSOD3基因呈诱导性表达,5mmol/L时表达量最高。通过RNAi策略技术成功敲低MdSOD3表达水平。将RNA干扰60h的幼虫置于5mmol/LCd2+处理24h后死亡率明显升高,并且出现中毒表象。NBT活性染色检测到体外重组表达的MdSOD3具有明显的酶活性。结果提示MdSOD3基因可能在家蝇抗逆防御过程中起着重要作用。As a member of the antioxidant enzymes,superoxide dismutase（SOD） plays a key role in insect antioxidant protection system.In this study,the full-length cDNA of a SOD gene MdSOD3（GenBank accession no.JQ408979） from the housefly,Musca domestica,was cloned and characterized by RT-PCR,which is 817 bp in length,the open reading frame is 534 bp encoding 177 amino acid residues.The homologous alignment and phylogenetic tree indicate that the MdSOD3 from housefly belongs to Cu/ZnSOD family.The temporal expression profiling revealed that MdSOD3 was present in the fat body,gut,hemocytes and cuticle.The expression of MdSOD3 was enhanced by Cd stress.The highest expression level was found in treatment at 5 mmol/L Cd2＋ within a 24 h period.Quantitative PCR（qPCR） showed that mRNA level of MdSOD3 gene was reduced compared to the control by RNAi.High mortality was observed in the larvae treated with dsRNA of MdSOD3 for 60 h at 5 mmol/L Cd stress for 24 h.The RNAi of MdSOD3 gene resulted in the larval abdominal apex to become black.The results suggest that MdSOD3 may play an important role in adapting to heavy metal stress in housefly.

关 键 词：家蝇 超氧化物歧化酶 基因相对定量 RNA干扰 重金属胁迫 

分 类 号：Q966[生物学—昆虫学]