关键词: 意大利蝗, 存储蛋白, cDNA, 基因克隆, 表达模式

Abstract: 【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 cDNA of C. italicus Hex2 (CitHex2) 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 kDa and a theoretical pI of 6.01. The amino acid analysis suggested that CitHex2 is rich in phenylalanine and tyrosine (15.8% of the total aa). Gene expression analysis showed that CitHex2 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 CitHex2 is involved in the development of C. italicus and that it is also associated with reproduction.

Key words: Calliptamus italicus, hexamerin, cDNA, gene cloning, expression pattern