昆虫钠离子通道的研究进展

昆虫只有一个或两个电压门控钠离子通道α亚基基因,但两种转录后修饰(选择性剪切和RNA编辑)实现了昆虫钠离子通道的功能多样性。昆虫β辅助亚基TipE和TEH1-4在钠离子通道表达和调控中也起着重要作用。电压门控钠离子通道在动作电位的产生和传递中至关重要,是多种天然和人工合成神经毒素及杀虫剂的作用靶标,包括广泛使用的拟除虫菊酯类、茚虫威和氰氟虫腙等杀虫剂。其中,拟除虫菊酯类杀虫剂通过调控昆虫钠离子通道的失活和去激活,延长跨膜钠离子流的时间,引起神经兴奋性传导障碍;茚虫威和氰氟虫腙阻断昆虫中枢和外周神经系统神经元的动作电位传导,这些神经毒剂都能干扰昆虫钠离子通道的正常功能。昆虫钠离子通道一般存在两个拟除虫菊酯类杀虫剂结合位点,但不同物种钠离子通道与拟除虫菊酯的结合位点存在一定差异。据此,本文就昆虫钠离子通道及其与杀虫剂的相互作用加以综述,有望推动昆虫神经受体研究,且对鉴定昆虫抗药性相关突变位点和研发高效的杀虫剂均具有重要参考价值。

Response of Cytochrome P450 Expression to Maize Volatiles in Helicoverpa armigera (Hner)

The 7-ethoxycoumarin O-deethylase （ECOD） activities of cytochrome P450s and differential expression of six cytochrome P450 genes induced by the volatiles from both damaged and undamaged maize plants were investigated in the cotton bollworm, Helicoverpa armigera （Hiabner）. The ECOD activity changed with time of exposure to maize volatiles. At 36 h after cotton bollworm larvae exposure to maize volatiles, the ECOD activities in cotton bollworm damaged and artificially damaged groups were 2.36 and 4.53 times higher than the control group respectively. The relative expression levels of CYP4S1, CYP6B2 and CYP6B7 in the cotton bollworm were significantly increased in artificially damaged plant group, which was 2.93, 5.09 and 10.66 times higher than that in the control group, respectively. The expression levels of CYP6B2, CYP6B6, CYP9A12, and CYP9A14 were much lower in the larvae exposure to volatiles from both healthy and pest damaged maize seedlings than in the control group at 12 h after larvae exposure to maize volatiles. For the cotton bollworm damaged maize group, the expression of CYP4S1 and CYP9A14 increased.

白纹伊蚊电压门控钠离子通道基因克隆及其生物信息学分析

目的电压门控钠离子通道是拟除虫菊酯类杀虫剂作用的特异性靶标位点,获得白纹伊蚊电压门控钠离子通道编码基因cDNA序列,通过生物信息学技术分析其分子特征,为研究白纹伊蚊对拟除虫菊酯类杀虫剂产生靶标抗性的分子机制奠定基础。方法通过反转录-聚合酶链式反应(RT-PCR)技术克隆获得白纹伊蚊钠离子通道基因序列,利用生物信息学技术分析其生物学特征。结果白纹伊蚊钠离子通道基因全长为6 357 bp,编码2 118个氨基酸,等电点为5.06,蛋白相对分子质量为237×10^(3)。发现3个选择性剪接(m、h、d)和6个RNA编辑位点。BLAST序列分析表明,白纹伊蚊与埃及伊蚊钠离子通道基因具有很高的同源性,相似度高达96.30%,克隆所得白纹伊蚊钠离子通道基因序列符合昆虫钠离子通道基因的基本特征。结论克隆获得了白纹伊蚊钠离子通道编码基因全长cDNA序列,并分析了其生物信息学特征,有助于阐明抗性机制和新靶点的研究开发,特别是对拟除虫菊酯类杀虫剂产生的靶标抗性分子检测具有重要意义。

乌鲁木齐郊区某崩塌地质灾害特征及成因机制分析

研究区崩塌位于乌鲁木齐郊区景观台两侧,岩层破碎,因崩塌体变形影响道路通行及游人安全。文章对崩塌的调查情况进行了阐述,对危岩带及危岩体特征展开了逐一分析,对其形成机制和影响因素进行了深入的研究。通过研究掌握此类崩塌体的变形特征和成因机制,为后期灾害防治提供基础,也为同类型的灾害发育特征和变形方式起到指导作用。