家蚕丝氨酸蛋白酶抑制剂BmSPI37的克隆、表达及微生物诱导分析

Cloning, Expression and Microbial-Induction Analysis of Bombyx mori Serine Protease Inhibitor BmSPI37

【目的】鉴定新的家蚕蛋白酶抑制剂,探讨其在抵御病原微生物入侵方面的功能。【方法】对家蚕蛋白酶抑制剂BmSPI37进行T-A克隆、多序列比对、系统发育树构建、原核表达、RT-PCR时空表达特征及微生物诱导分析。【结果】克隆、表达了1个新的丝氨酸蛋白酶抑制剂,命名为BmSPI37。时空表达特征分析表明,BmSPI37在家蚕5龄幼虫后期表达量很高,而且在中部丝腺中高量表达;在蛹向蛾的变态发育时期,BmSPI37在雌蚕中的表达量显著高于雄蚕。微生物诱导试验表明,BmSPI37在大肠杆菌、黑胸败血菌、球孢白僵菌感染后,强烈上调表达。【结论】推测BmSPI37与防御病原微生物入侵有关。

[ Objective ] The objective of this study is to identify a new protease inhibitor of silkworm （Bombyx mori） and to investigate its function in guarding against invasion of pathogenic microorganisms. [Method] T-A cloning, multiple sequence alignment, construction of phylogenetic tree, prokaryotic expression, spatio-temporal expression profile analysis and microbial-induced experiments were performed with BmSPI37. [ Result ] A new serine proteinase inhibitor, named BmSPI37, was cloned and expressed. Spatio-temporal expression profile analysis showed that BmSPI37 expressed highly at the late stage of 5th instar larvae, and expressed highly in the middle silk gland. The expression of BmSPI37 was significantly higher in female than in male during metamorphosis period from pupa to moth. Analysis of the expression of BmSPI37 after infection with Escherichia coli, Bacillus bombysepticus or Beauveria bassiana showed that BmSPI37 was strongly up-regulated. [ Conclusion ] It is speculated that BmSPI37 is related to defense against pathogenic microorganisms.