香梨优斑螟脂肪酸Δ9去饱和酶基因序列及不同虫态的表达分析

Gene Sequences and Expression Analysis of Fatty Acid Δ9 Desaturase of Euzophera pyriella during Different Stages

【目的】研究Δ9去饱和酶基因特性及其在不同虫态下的表达,研究EpFAD9基因功能及潜在应用提供数据,为该香梨优玫玉暝、饱和脂肪酸积累中的作用提供参考。【方法】采用生物信息学软件鉴定、分析和预测Δ9去饱和酶(EpFAD9)的核苷酸和氨基酸序列,研究蛋白质结构和功能,并利用qRT-PCR方法测定△9去饱和酶基因在不同虫态下的表达水平。【结果】EpFAD9基因开放阅读框由1 056 bp组成,含352个氨基酸,起始密码子ATG位于获得序列的第1 280碱基上,终止密码子TAA位于该序列第2 338碱基。推测该蛋白无信号肽,共4个跨膜结构域,整体表现为亲水性蛋白,主要在内质网中发挥生物学作用。EpFAD9基因在幼虫期表达量较高,分别是成虫期和蛹期的17.75和29.58倍。【结论】EpFAD9基因基因在香梨优斑螟不同虫态下存在表达差异,在幼虫体内的表达量最高,成虫和蛹期的表达很低,尤其是虫蛹,其表达量更低于成虫,虫蛹和成虫状态下的香梨优斑螟对低温抵抗能力都低于幼虫。

【Objective】 The Δ9 desaturase gene in Euzophera pyriella plays an important role in the accumulation of unsaturated fatty acids, so this project aims to clarify the characteristics of the gene and its expression in different insect states. 【Method】This study aimed to identify, analyze, and predict the nucleotide and amino acid sequences of Δ9 desaturase in Euzophera pyriella(EpFAD9) using bioinformatics software, and to deduce the structure and function of the protein. The mRNA expression of the EpFAD9 gene in different stages of E. pyriella was also determined by RT-PCR.【Result】The open reading frame of EpFAD9 gene consisted of 1,056 bp and 352 amino acids. The start codon ATG was located at the 1,280 base of the obtained sequence, and the stop codon TAA was located at the 2,338 base of the sequence. It was speculated that the protein had no signal peptide but had four transmembrane domains, which behaved as a hydrophilic protein and played a biological role in the endoplasmic reticulum. The relative expression level of EpFAD9 gene was rich in larval stage, which was 17.75 times and 29.58 times higher than those in adult and sputum stages, respectively.【Conclusion】 The expression of EpFAD9 gene is different in different Euzophera pyriella states, and the expression level in larva was the highest, while that in adult and pupa was low, the pupa stage is the lowest, this shows that the resistance of pupa and adults to low temperature is lower than that of larvae.