家蚕表皮型几丁质合成酶基因BmCHSA-2a的鉴定及其对激素的响应  

Identification of Epidermal Chitin Synthase BmCHSA-2a in Bombyx mori and Its Responses to Hormones

作　　者：张捷 丁洋[1] 郑思春[1] 

机构地区：[1]华南师范大学生命科学学院∥广州市昆虫发育调控与应用研究重点实验室,广州510631

出　　处：《华南师范大学学报（自然科学版）》2018年第1期65-71,共7页Journal of South China Normal University(Natural Science Edition)

基　　金：国家重点基础研究发展计划(973计划)项目(2012CB114603);国家高技术研究发展计划(863计划)项目(2011AA10A204-3)

摘　　要：文中采用5'Race方法获得了家蚕几丁质合成酶基因(BmCHSA-2a)的第1外显子(Exon 1,141 bp)和第2外显子(Exon 2a,106 bp),证明外显子2a在鳞翅目昆虫几丁质合成酶中高度保守.根据该外显子序列设计引物,分析BmCHSA-2a对激素的响应,结果表明:蜕皮激素(Ecdysone,20E)抑制BmCHSA-2a的表达;保幼激素(Juvenile Hormone,JH)间接促进其表达.根据家蚕基因组所预测的启动子序列,扩增了调控BmCHSA-2a表达的启动子,证明蜕皮激素抑制启动子活性,并存在大量蜕皮激素通路BmFTZ-F1的调控元件.对BmFTZ-F1表达调控的进一步研究表明:蜕皮激素抑制其表达.研究结果初步分析了家蚕表皮几丁质合成酶基因BmCHSA-2a可能的表达机制,为深入研究其表达调控机理及发现害虫防治新靶标提供了理论基础.In this study,the exon 1( 141 bp) and exon 2 a( 106 bp) of Bm CHSA-2a were cloned by the 5'Race method. The mRNA levels of Bm CHSA-2a in response to hormones were analyzed using the primers based on the sequence of exon 2 a,which is conservative in insects. The results showed that the expression of Bm CHSA-2a was inhibited by ecdysone( 20 E),but was indirectly induced by juvenile hormone( JH). Promoter activity determination confirmed that the transcription of Bm CHSA-2a was inhibited. Further analysis revealed that a lot of Bm FTZF1 cis-regulation elements exist in the promoter sequence of Bm CHSA-2a,and the expression of transcription factor Bm FTZ-F1 was inhibited by 20 E. The results demonstrate the relationship between hormones and Bm CHSA-2a and provide the foundation for further study of possible target gene used for pest control.

关 键 词：家蚕 表皮几丁质合成酶 可变剪切 激素 表达 

分 类 号：Q966[生物学—昆虫学]