COMPARISON OF BACILLUS-THURINGIENSIS SUBSP ISRAELENSIS CRYIVA AND CRYIVB CLONED TOXINS REVEALS SYNERGISM INVIVO
COMPARISON OF BACILLUS-THURINGIENSIS SUBSP ISRAELENSIS CRYIVA AND CRYIVB CLONED TOXINS REVEALS SYNERGISM INVIVO
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DOI：
10.1111/j.1574-6968.1992.tb05290.x
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发表时间：
1992-07-01
影响因子：
2.1
通讯作者：
ELLAR, DJ
中科院分区：
文献类型：
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作者：
ANGSUTHANASOMBAT, C;CRICKMORE, N;ELLAR, DJ
当杀蚊蛋白 CryIVA 的基因在两株苏云金芽孢杆菌 (Bt) 中表达时，其固有的 δ-内毒素基因被清除，该蛋白以大内含物的形式积累。 Bt 亚种产生的内含物。 kurstaki 受体菌株在碱性 pH 值下的可溶性是 Bt 亚种中产生的内含物的两倍。以色列人。通过用蚊子肠道提取物或胰蛋白酶处理不同时间长度来激活溶解的原毒素，并测试对三个蚊属细胞系的体外细胞毒性。用任何蚊子肠道提取物处理 CryIVA 6 小时，对冈比亚按蚊细胞显示出显着的毒性，对致倦库蚊细胞有轻微活性。对于 CryIVB，观察到的唯一显着的细胞毒性是用伊蚊肠道提取物处理后针对埃及伊蚊细胞的细胞毒性。在体内生物测定中，从任一 Bt 受体菌株纯化的 CryIVA 和 CryIVB 内含物对埃及伊蚊和冈比亚伊蚊幼虫的毒性相似，但 CryIVA 对致倦库蚊的毒性高出 25 倍。当比较单一毒素和混合物的测定结果时，揭示了两种毒素之间的体内协同作用。事实证明，CryIVA 和 CryIVB 的混合物对库蚊的毒性比单独使用的任何一种毒素高 5 倍，并且在针对伊蚊和按蚊幼虫进行测试时，显示出减弱但相似的协同作用。使用这三种昆虫的细胞系在体外没有重复这种协同作用。
When the gene for the mosquitocidal protein CryIVA was expressed in two strains of Bacillus thuringiensis (Bt) cured of their resident delta-endotoxin genes, the protein accumulated as large inclusions. The inclusions produced in the Bt subsp. kurstaki recipient strain were twice as soluble at alkaline pH as the inclusions produced in Bt subsp. israelensis. Solubilized protoxins were activated by treatment with mosquito gut extracts or trypsin for varying lengths of time and tested for in vitro cytotoxicity on cell lines of three genera of mosquito. CryIVA treated with any of the mosquito gut extracts for 6 h showed significant toxicity against Anopheles gambiae cells and slight activity on Culex quinquefasciatus cells. For CryIVB, the only significant cytotoxicity observed was against Aedes aegypti cells after treatment with Aedes gut extract. In in vivo bioassays, both CryIVA, purified from either of the Bt recipient strains, and CryIVB inclusions were similarly toxic to A. aegypti and A. gambiae larvae but CryIVA was 25-fold more toxic to C quinquefasciatus. Synergism in vivo between the two toxins was revealed when results from assaying single toxins and mixtures were compared. Mixtures of CryIVA and CryIVB proved to be 5-fold more toxic to Culex than either toxin used singly and showed a reduced but similar synergism when tested against Aedes and Anopheles larvae. The synergism was not duplicated in vitro using cell lines from these three insects.