苜蓿盲蝽气味结合蛋白基因Alin-OBP1的克隆及表达谱分析

有证据表明昆虫气味结合蛋白(odorant binding proteins, OBPs)与其嗅觉识别密切相关,起着运输外界脂溶性气味分子通过嗅觉感器淋巴液到达嗅觉受体的关键作用.为了更好地了解OBPs在苜蓿盲蝽Adelphocoris lineolatus (Goeze)嗅觉识别中的作用,本研究首次克隆了苜蓿盲蝽气味结合蛋白基因Alin-OBP1 (GenBank序列号GQ477022). 测序和序列分析结果表明,该基因开放阅读框长438 bp, 编码145个氨基酸,预测分子量为15.69 kDa,等电点为5.01,N-末端疏水区包含由18个氨基酸组成的信号肽.蛋白特征分析表明,该基因翻译后的蛋白质具有昆虫气味结合蛋白的典型特征,即氨基酸序列中有6个保守的半胱氨酸残基.利用RT-PCR和Real-time PCR技术对Alin OBP1在苜蓿盲蝽成虫不同组织和各个发育阶段的表达水平进行了测定,结果显示Alin-OBP1几乎全部在触角中表达.不同发育阶段Alin-OBP1表达量不同,在5龄若虫和成虫阶段表达水平最高.结果提示Alin-OBP1可能在苜蓿盲蝽感受包括性信息素在内的外界化合物的过程中发挥着重要作用.

Cloning and expression pattern analysis of an odorant binding protein gene Alin-OBP1 in the lucerne plant bug, Adelphocoris lineolatus (Goeze)(Hemiptera:Miridae)

In order to study the relationship between resistance and sex in male and female Bombyx mori, Thermo enzyme activity measurement and Real Time fluorescent quantitative RT-PCR were performed to compare differences of the activities of detoxification enzymes in male and female B. mori larvae and their genetic expression of newly exuviated larvae at different instars. The research demonstrated significant differences in detoxification enzymes and their related genes existed between male and female B mori larvae. The activities of glutathione S-transferases（GSTs）and BmGSTe5 showed higher expression in males than those in 1st-3rd instar females, while the opposite phenomena were found in 4th and 5th instar larvae. The ratios of enzyme activity and gene expression in the male and the female were 3.65 and 5.11, respectively, which were attributed to the fast development of testis in 4th instar larvae. The enzyme activities of acetylcholine esterase（AchE） in the male were 1.48,1.34 and 1.40 times compared to those of the female from 2nd to 4th instars, while its gene Bm-ace1 showed insignificant differences between male and female B. mori at 2nd and 3rd instars. The expression amount of gene Bm-ace2 in the male were 1.75,2.17 and 2.40 times as high as that in the female from 2nd to 4th instars, suggesting that Bm-ace2 plays a more important role in sex differences. The enzyme activities of carboxylesterase （CarE） in male were 1.23 and 1.87 times compared to that in female at 2nd and 3rd instars, and the activity ratios in the female and the male were 1.22 and 1.23 at 4th and 5th instars, respectively. The expression of BmCarE-5 and BmCarE-10 showed the opposite trend to enzyme activities between different sexes, i.e., low level gene expression and high carboxylesterase activity. We so speculate that carboxylesterase mutation phenomenon exists in B.mori. These results break a new road for research on modification of genetic expression products and their function, and make further contribution to the study of relations between the gender and the ability of drug resistence in B. mori.