Talbot W S, Swyryd E A, Hogness D S
Department of Biochemistry, Stanford University School of Medicine, California 94305.
Cell. 1993 Jul 2;73(7):1323-37. doi: 10.1016/0092-8674(93)90359-x.
In D. melanogaster a pulse of the steroid hormone ecdysone triggers the larval-to-adult metamorphosis, a complex process in which this hormone induces imaginal tissues to generate adult structures and larval tissues to degenerate. We show that the EcR gene encodes three ecdysone receptor isoforms (EcR-A, EcR-B1, and EcR-B2) that have common DNA- and hormone-binding domains but different N-terminal regions. We have used isoform-specific monoclonal antibodies to show that at the onset of metamorphosis different ecdysone target tissues express different isoform combinations in a manner consistent with the proposition that the different metamorphic responses of these tissues require different combinations of the EcR isoforms. We have also determined temporal developmental profiles of the EcR isoforms and their mRNAs in whole animals, showing that different isoforms predominate at different developmental stages that are marked by a pulse of ecdysone.
在黑腹果蝇中，类固醇激素蜕皮激素的脉冲触发幼虫到成虫的变态，这是一个复杂的过程，在此过程中这种激素诱导成虫组织生成成虫结构，幼虫组织退化。我们发现EcR基因编码三种蜕皮激素受体亚型（EcR-A、EcR-B1和EcR-B2），它们具有共同的DNA和激素结合结构域，但N端区域不同。我们使用亚型特异性单克隆抗体表明，在变态开始时，不同的蜕皮激素靶组织以与这些组织不同的变态反应需要不同的EcR亚型组合这一观点一致的方式表达不同的亚型组合。我们还确定了全动物中EcR亚型及其mRNA的时间发育谱，表明不同的亚型在以蜕皮激素脉冲为标志的不同发育阶段占主导地位。
