意大利蝗存储蛋白Hex2基因的克隆与表达分析(英文)

Cloning and expression analysis of the hexamerin subunit type 2 (Hex2) gene from the grasshopper Calliptamus italicus( Orthoptera: Catantopidae)

【目的】昆虫存储蛋白（hexamerin）是在昆虫体内独立发生普遍存在的一种特异性淋巴蛋白,在昆虫的生长发育过程中起重要作用。【方法】克隆意大利蝗Calliptamus italicus的存储蛋白Hex2基因,并利用qRT-PCR方法分析其在不同组织和不同发育阶段的表达模式。【结果】克隆到意大利蝗存储蛋白Hex2基因Cit Hex2,其cDNA全序列长2 610 bp,开放阅读框（ORF）长为2 022 bp,3＇非翻译区（UTR）长为124 bp,碱基序列与其他蝗虫的Hex2基因核苷酸一致性为80%~84%。Cit Hex2编码673个氨基酸,预测分子量和等电点分别为78.7 k Da和6.01。氨基酸分析表明,Cit Hex2富含较高的芳香族氨基酸,其中苯丙氨酸和酪氨酸共占15.8%。定量分析结果表明,Cit Hex2在意大利蝗的整个发育阶段都有表达,且在每个龄期的蜕皮前后均有表达量的变化;在检测的所有组织中,雌性个体的表达量较高。【结论】Cit Hex2参与意大利蝗的发育过程,与其生殖有关。

【Aim】Hexamerins are large hemolymph-proteins that accumulate in insects during the late larval stages and serve important roles throughout insect development and growth. 【Methods】Our study cloned the hexamerin subunit type 2（ Hex2） gene from the grasshopper Calliptamus italicus and by using qRT-PCR method analysed its expression patterns in different tissues and at different developmental stages. 【Results】The c DNA of C. italicus Hex2（Cit Hex2） is 2 610 bp in length,containing a 2 022 bp open reading frame（ORF）and a 124 bp 3＇ untranslated region（ UTR）. BLAST analysis showed that it shares 80%- 84% nucleotide sequence identity with Hex2 genes from other grasshoppers. The encoded protein was predicted to be 673 aa in length with an estimated molecular weight of 78. 7 k Da and a theoretical p I of 6. 01. The amino acid analysis suggested that Cit Hex2 is rich in phenylalanine and tyrosine（ 15. 8% of the total aa）. Gene expression analysis showed that Cit Hex2 was expressed at all developmental stages but was differentially expressed during juvenile stages and more highly expressed in female tissues than in male tissues. 【Conclusion】These findings show that Cit Hex2 is involved in the development of C. italicus and that it is also associated with reproduction.