Edysone receptor isoforms play distinct roles in controlling molting and metamorphosis in the red flour beetle, Tribolium castaneum
Edysone receptor isoforms play distinct roles in controlling molting and metamorphosis in the red flour beetle, Tribolium castaneum
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DOI：
10.1016/j.mce.2008.05.006
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发表时间：
2008-09-10
影响因子：
4.1
通讯作者：
Palli, Subba Reddy
中科院分区：
文献类型：
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作者：
Tan, Anjiang;Palli, Subba Reddy
蜕皮激素通过由蜕皮激素受体（EcR）和超囊泡（USP）组成的核受体异二聚体复合物调节昆虫的生长发育。在红粉甲虫Tribolium castaneum中，已鉴定出EcR和USP的两个同工型。定量实时逆转录酶PCR （qRT-PCR）分析显示，EcR和USP在末龄幼虫和蛹的表皮和中肠中均有异构体特异性表达。注射用EcR或USP的共同区域或同种异构体特异性区域制备的双链RNA （dsRNA）作为模板导致发育脱轨。EcR共区（EcRC）或EcRA dsRNA的作用更为严重，处理后的幼虫大多在化蛹前死亡。EcRB dsRNA对幼虫的影响较小，处理后的幼虫大多成蛹，但表现出发育缺陷。只有针对USP共同区制备的dsRNA，而不针对USDA或USPB异构体特异性区制备的dsRNA在幼虫蛹蜕变过程中引起发育缺陷。qRT-PCR检测EcRA、EcRB或EcRC dsRNA注射的幼虫EcR异构体和20-羟基脱皮激素反应（20E）基因（broad、E75、E74、HR3和FTZ-F1） mRNA水平表明，EcRA通过调控EcRB和20E反应基因的表达来启动脱皮激素作用。这些数据表明，EcR而非USP亚型在castaneum幼虫-蛹蜕变过程中发挥着不同的作用，EcRA在castaneum表皮甾体反应的转导中起主导作用。2008爱思唯尔爱尔兰有限公司版权所有。
Ecdysteroids regulate insect growth and development through a heterodimeric complex of nuclear receptors consisting of ecdysone receptor (EcR) and ultraspiracle (USP). In the red flour beetle, Tribolium castaneum, two isoforms each of EcR and USP have been identified. Quantitative real-time reverse-transcriptase PCR (qRT-PCR) analysis showed isoform-specific developmental expression of both EcR and USP in the epidermis and the midgut dissected from the final instar larvae and pupae. Injection of double-stranded RNA (dsRNA) prepared using the common or isoform-specific regions of EcR or USP as templates caused derailment of development. EcR common region (EcRC) or EcRA dsRNA caused more severe effects, and most of the treated larvae died prior to pupation. EcRB dsRNA caused less severe effects and most of the treated larvae became pupae but showed developmental defects. Only dsRNA prepared against USP common region but not against USDA or USPB isoform-specific region caused developmental defects during larval-pupal metamorphosis. Determination of mRNA levels of EcR isoforms and 20-hydroxyecdysone-response (20E) genes (broad, E75, E74, HR3 and FTZ-F1) by qRT-PCR in the larvae injected with EcRA, EcRB or EcRC dsRNA showed that EcRA initiates ecdysteroid action by regulation the expression of EcRB and 20E-response genes. These data suggest that the EcR but not USP isoforms play distinct roles during the larval-pupal metamorphosis and EcRA plays a dominant role in transduction of ecdysteroid response in T. castaneum. (c) 2008 Elsevier Ireland Ltd. All rights reserved.