飞蝗可溶型海藻糖酶基因的序列分析及mRNA表达特性

Sequence characterization and mRNA expression profiling of a soluble trehalase gene in Locusta migratoria (Orthoptera: Acrididae)

海藻糖酶是海藻糖代谢过程中的一个关键酶,在昆虫发育和能量调节中具有重要作用,为进一步探讨海藻糖酶基因的功能,本文分析了飞蝗Locusta migratoria一可溶型海藻糖酶基因的氨基酸序列并对其mRNA表达特性进行了研究。结果表明:该海藻糖酶(TRE,GenBank登录号:FJ795020)不含有跨膜结构。系统进化树分析结果显示,该酶与大豆蚜Aphis glycines、豌豆蚜Acyrthosiphon pisum、褐飞虱Nilaparvata lugens和灰飞虱Laodelphax striatella可溶型海藻糖酶具有较近的亲缘关系,因此我们将该酶的基因命名为LmTre-1。对该基因在不同组织和发育时期表达量的荧光定量PCR分析表明:LmTre-1在卵发育前期、中期的表达量都很低,卵发育后期表达量显著提高;LmTre-1在5龄若虫和成虫被检测的组织部位中均有表达,在体壁中的表达量最高,其次是在脂肪体、肌肉、气管、精巢及卵巢中;5龄飞蝗刚蜕皮后LmTre-1在体壁中的表达量较高,随着生长发育其表达量逐渐降低;LmTre-1在成虫发育期体壁中稳定高表达。LmTre-1的mRNA表达特性与几丁质合成酶1基因非常相似,据此推测该基因可能与体壁几丁质的合成相关。本研究为深入探讨该基因的生理功能提供了重要的基础数据,并为以海藻糖酶为杀虫靶标的农药筛选奠定实验基础。

Trehalase is a key enzyme in trehalose metabolism and plays important roles in the development and regulation of energy in insects. In order to further investigate the function of trehalase, we analyzed the molecular characteristics and mRNA expression pattern of a soluble trehalase （TRE, GenBank accession no. FJ795020 ） gene from Locusta migratoria. No transmembrane region was predicted for TRE of L. migratoria. Phylogenetic analysis showed that TRE of L. migratoria was first clustered with soluble trehalases of Aphis glycines, Acyrthosiphon pisum, Nilaparvata lugens and Laodelphax striatella, and its gene was so designated as LmTre-1. qPCR was used to analyze the mRNA expression pattern of LmTre-I in different tissues and developmental stages in L. migratoria. The expression of LmTre-I was low in early and middle stage eggs but greatly increased in late stage eggs. Tissue-specific expression results showed that LmTre-1 was expressed in all the major tissues, with high expression level in integument and lower expression level in fat body, muscles, trachea, testis and ovaries in the 5th instar nymphs and adults. LmTre-1 was also highly expressed after molting and the expression level gradually declined during the 5th instar nymphal development. LmTre-1 was constantly expressed at a high level in chitin synthase 1 gene, and the integument of adults. This it is so inferred that LmTre-1 is The study sheds new light on a better understanding of the pave a way for pesticide screening based on trehalase. expression pattern is very similar with that of associated with chitin synthesis in the cuticle. functional characteristics of this gene and may