亚洲玉米螟几丁质合成酶B(CHSB)启动子序列克隆与分析

Cloning and analysis of Ostrinia furnacalis chitin synthase B(CHSB)promoter sequence

昆虫几丁质合成酶是昆虫蜕皮和变态发育过程中几丁质生物合成的关键酶,同时也是环境友好杀虫剂的理想靶标。昆虫几丁质合成酶可分为两类,即A类和B类。其中A类几丁质合成酶(CHSA)主要合成昆虫表皮的几丁质,而B类几丁质合酶(CHSB)在围食膜的形成阶段表达。从亚洲玉米螟3龄幼虫体内提取基因组DNA,利用染色体步移获得了CHSB完整的启动子序列。该DNA片段长度为1484 bp,分析显示该片段为Of CHSB基因5'端侧翼序列,转录起始位点从+1开始,Of CHSB的开放阅读框从+348至+402,分析表明6种类似的转录因子(GATA-1、C/EBPalpha、Oct-1、Dfd、CREB、ER)可能参与Of CHSB的转录调控。转录因子结合位点分别于+116至+127(CREB)、+120至+131(ER)和+292至+302(Oct-1)的区域可能是该启动子的核心顺式元件。

Insect chitin synthase is the key enzyme of chitin biosynthesis in insect molting and metamorphosis process, and also is the ideal target of environmental friendly insecticides. Insect chitin synthase can be divided into two categories, namely the class A and B. Class A chitin synthase （CHSA） synthase chitin to form insect cuticle, and class B chitin synthase （CHSB） involved in the formation of peritrophic membrane. In this study, the 5＇ flanking sequence （1484 bp ） of CHSB which contains complete promoter sequence was obtained from third instar larvae of Asian corn borer by using genome walker. Sequence analysis shows that transcription factor binding sites distributed in 1082 to ＋ 347 regions in the 5＇ flanking sequence of CHSB gene. Six possible homogenous transcription factors binding sites were predicated out. Among these c/s elements, ＋ 116 to ＋ 127 （CREB）, ＋ 120 to ＋ 131 （ER） and ＋ 292 to ＋ 302 （ Oct - 1 ） regions may consist the core cis elements of this promoter.