摘要
核受体基因家族是介导昆虫蜕皮激素(20E)作用的关键信号分子。为了研究家蚕丝腺中核受体异源二聚体编码基因——蜕皮激素受体基因Bm EcR和超气门蛋白基因Bm USP的表达模式,应用实时荧光定量PCR技术检测家蚕5龄幼虫正常状态下和用2×10^(-3)μg/μL蜕皮激素处理后Bm EcR与Bm USP在丝腺组织中的表达变化。结果表明,20E处理后,Bm EcRA、Bm EcR-B1和Bm USP在中、后部丝腺的表达量与对照组相比均有不同程度增加,说明20E能够促进Bm EcR-A、Bm EcR-B1和Bm USP基因的表达;但中部丝腺与后部丝腺Bm EcR-A、Bm EcR-B1和Bm USP基因的表达变化趋势不同。利用等温滴定量热技术(ITC)获得的家蚕蜕皮激素受体结构域蛋白Bm EcR-B1D与蜕皮激素响应元件Bm E75A-EcRE及其缺失突变体相互作用的亲和力常数(K)、反应热(ΔH)和熵(ΔS),显示了Bm EcR-B1D蛋白能够与Bm E75A-EcRE进行结合,并发现Bm E75A-EcRE的核心保守区为编码序列TCTTC,推测该区域有可能是Bm EcR-B1D蛋白结合在Bm E75A-EcRE上的精确位点。
Nuclear receptor gene family includes key signal molecules which mediate function of insect molting hormone.To investigate the expression patterns of nuclear receptor heterodimer-encoding gene namely ecdysone receptor gene Bm EcR and ultraspiracle gene Bm USP in silk gland of Bombyx mori,the expression changes of Bm EcR and Bm USP in silk gland of the 5th instar larvae under normal condition and treated with 2 × 10- 3μg /μL ecdysone（ 20E） were detected using real-time quantitative PCR（ qRT-PCR） technology. The expression level of Bm EcR-A,Bm EcR-B1 and Bm USP in middle and posterior silk gland was increased at various degrees after treated with 20 E,indicating that 20 E can promote the expression of these three genes. However,the expresssion characteristics of these three genes were different in middle silkgland and posterior silk gland. We used isothermal titration calorimetry technology（ ITC） to obtain affinity constant（ K）,reaction heat（ ΔH） and entropy（ ΔS） of interaction among Bm EcR-B1 domain（ Bm EcR-B1D）,ecdysone receptor element Bm E75A-EcRE and its deletion mutants. The results showed that Bm EcR-B1 D protein could bind with Bm E75A-EcRE which had a core conserved region of TCT-TC,suggesting that this region is the exact site where Bm EcR-B1 D protein binds with Bm E75A-EcRE.
出处
《蚕业科学》
CAS
CSCD
北大核心
2016年第3期425-431,共7页
ACTA SERICOLOGICA SINICA
基金
现代农业产业技术体系建设专项(No.CARS-22)
