舞毒蛾气味结合蛋白基因克隆及对CO2胁迫的响应

气味结合蛋白（OBPs）可以特异性地结合并运输气味分子，在昆虫嗅觉系统感受气味分子过程中发挥重要作用。为探讨舞毒蛾OBP基因特性及对CO₂浓度升高的响应规律，克隆了2个舞毒蛾OBP基因，利用生物信息学分析其基因特性，并通过qRT−PCR技术研究不同CO₂浓度下OBP基因组织特异性表达。结果表明LdOBP1和LdOBP2基因开放阅读框（ORF）分别为450 bp和417 bp，编码149和138个氨基酸，蛋白质分子量为19.41 kDa和15.35 kDa，理论等电点为11.17和6.73，LdOBP1为碱性蛋白，LdOBP2为酸性蛋白。LdOBP1和LdOBP2均无明显跨膜区域，LdOBP1无信号肽序列，而LdOBP2在1～22位有信号肽序列。进化树分析表明舞毒蛾LdOBP1和LdOBP2分别与桃小食心虫OBP（AYD42195.1和AYD42180.1）亲缘关系较近。舞毒蛾OBPs基因均在幼虫头部表达水平最高。高浓度CO₂下显著抑制了舞毒蛾幼虫各组织LdOBP1基因的表达，而LdOBP2基因在高浓度CO₂下头部和中肠表现出不同程度的诱导上升。舞毒蛾OBPs基因均在成虫触角表达水平最高，高浓度CO₂下显著抑制舞毒蛾雌、雄成虫触角LdOBP1和LdOBP2基因表达。舞毒蛾可能通过调控各组织OBPs基因的表达水平来响应CO₂胁迫。

Cloning of Odorant Binding Protein Gene in Lymantria dispar and Its Response to CO2 Stress

Odorant binding proteins(OBPs) can specifically bind and transport odor molecules, which play an important role in sensing odorants in insect olfactory system. The characteristics of the OBP gene in Lymantria dispar and its response to elevated CO2 concentration were studied in order to provide a theoretical basis for clarifying the olfactory response mechanism of the L. dispar under global climate change. Two OBP genes in L. dispar were cloned and its characteristics were analyzed by bioinformatics. Tissue specific expressions of OBP genes were determined under different CO2 concentrations by qRT-PCR. The results showed that the open reading frame(ORF) length of LdOBP1 and LdOBP2 genes are 450 bp and 417 bp, which are encoding 149 and 138 amino acids, respectively. The molecular mass of the protein is 19.41 kDa and 15.35 kDa, and the theoretical isoelectric points are 11.17 and 6.73 for LdOBP1 and LdOBP2, respectively. The LdOBP1 is alkaline protein and LdOBP2 is acidic protein. Both LdOBP1 and LdOBP2 have no obvious transmembrane region. LdOBP1 has no signal peptide sequence while LdOBP2 has signal peptide sequence from 1–22. Phylogenetic tree analysis showed that LdOBP1 and LdOBP2 in L. dispar are closely related to the OBP(AYD42195.1) and OBP(AYD42180.1) in Carposina sasakii, respectively. The OBPs genes in the L. dispar larvae had the highest expression levels in the head. High concentration of CO2 significantly inhibited the expression of LdOBP1 genes in the L. dispar tissues, while LdOBP2 gene expressions were induced in the head and midgut. The OBP genes in L. dispar have the highest expression levels in adult antennae. The expression of LdOBP1 and LdOBP2 genes were significantly inhibited in the antennae of L. dispar adult under high concentration of CO2 stesses. L. dispar may be respond to CO2 stress by regulating the expression level of OBP genes in various tissues.