【摘要】 九香虫Coridius chinensis是我国一种重要的药食两用昆虫,溶菌酶是一种具有抗菌作用的糖苷水解酶。该研究从九香虫中克隆了一种溶菌酶基因CcLys,其cDNA长883 bp,包含一个669 bp的开放阅读框,编码222个氨基酸。九香虫溶菌酶CcLys的N-端包含一段由18个氨基酸组成的信号肽,成熟CcLys形成7个α-螺旋,8个β-折叠片的三维结构。同源性和聚类分析显示CcLys与茶翅蝽Halyomorpha halys溶菌酶的亲缘关系最近。基因表达谱分析表明,CcLys在九香虫的整个发育阶段都有表达,在3龄若虫中表达水平最高;该基因在所检测的成虫组织中都有表达,在脂肪体中表达水平最高。成虫被细菌诱导后,CcLys的表达水平在12 h达到峰值。该研究为进一步明确CcLys基因的功能及开发新型抗菌药物奠定基础。更多还原

【Abstract】 Coridius chinensis is an important insect used for both medicine and food source in China,and lysozyme is a glycoside hydrolase with antimicrobial activity. In this study,alysozyme gene,designated CcLys,was cloned from C. chinensis. The CcLys cDNA was 883 bp in length which contained a 669 bp open reading frame(ORF) that encoded 222 amino acids. CcLys contained a signal peptide composed of 18 amino acids at N-terminus,and the mature CcLys formed a three-demensional structure consisted of 7 α-helix and 8 β-pleated sheets. Homology and cluster analyses showed that CcLys possesses the closest relationship with that of Halyomorpha haly. Gene expression analyses indicated that CcLys was expressed throughout the developmental stages of C. chinensis with the highest expression level in the 3 rd instar nymph,and this gene was expressed in the adult tissues tested with the highest expression level in the fat body. The mRNA expression level of this gene peaked at 12 h post induction by bacteria. This study will provide a foundation for further understanding the function of CcLys gene and developing new antimicrobial drugs.更多还原