Sun X, Song Q, Barrett B
Department of Entomology, University of Missouri, 1-87 Agriculture Building, Columbia, MO 65211, USA.
Insect Biochem Mol Biol. 2003 Aug;33(8):829-40. doi: 10.1016/s0965-1748(03)00082-1.
Tebufenozide and methoxyfenozide have been previously shown to significantly reduce fecundity and cause vitellogenin accumulation in hemolymph of the codling moth Cydia pomonella L. In the present study, the effects of these ecdysone agonists, tebufenozide and methoxyfenozide, on the expression of ecdysone receptor (EcR), ultraspiracle protein (USP) and other proteins in the ovaries of C. pomonella L., were investigated at both the translational and/or transcriptional levels with an aim to elucidate the mechanisms by which the fecundity was reduced. Western and Northern blot analyses revealed that the expression of a 65 kDa (p65) EcR, and 60 and 64 kDa (p60 and p64) USP proteins were enhanced by tebufenozide and methoxyfenozide at both transcriptional and translational levels. Northern blot analysis indicated that the p65 EcR protein is encoded by EcRB1 transcript and that the p60 and p64 USP bands were the products of USP-1 transcript. Immunoprecipitation assays demonstrated that both the p60 and p64 USP coprecipitated with the p65 EcR and that p64 was a dominant USP to form complex with EcR. In addition, several other specific proteins were also identified and their expressions affected by the agonists. The data suggest that the ecdysone agonists regulate, via the EcR/USP complex, the expression of these specific proteins that might eventually lead to the inhibition of fecundity in the codling moth.
虫酰肼和甲氧虫酰肼此前已被证明能显著降低苹果蠹蛾（Cydia pomonella L.）的繁殖力，并导致其血淋巴中卵黄原蛋白积累。在本研究中，研究了这两种蜕皮激素激动剂——虫酰肼和甲氧虫酰肼，在翻译和/或转录水平上对苹果蠹蛾卵巢中蜕皮激素受体（EcR）、超气门蛋白（USP）及其他蛋白质表达的影响，旨在阐明繁殖力降低的机制。蛋白质免疫印迹（Western blot）和RNA印迹（Northern blot）分析表明，虫酰肼和甲氧虫酰肼在转录和翻译水平上均增强了65 kDa（p65）EcR、60 kDa和64 kDa（p60和p64）USP蛋白的表达。Northern blot分析表明，p65 EcR蛋白由EcRB1转录本编码，p60和p64 USP条带是USP-1转录本的产物。免疫沉淀试验表明，p60和p64 USP均与p65 EcR共沉淀，且p64是与EcR形成复合物的主要USP。此外，还鉴定出了其他几种特定蛋白质，其表达受激动剂影响。数据表明，蜕皮激素激动剂通过EcR/USP复合物调节这些特定蛋白质的表达，这最终可能导致苹果蠹蛾繁殖力受到抑制。
