Kozlova Tatiana, Thummel Carl S
Howard Hughes Medical Institute, Department of Human Genetics, University of Utah School of Medicine, 15 North 2030 East Room 5100, Salt Lake City, UT 84112-5331, USA.
Science. 2003 Sep 26;301(5641):1911-4. doi: 10.1126/science.1087419. Epub 2003 Sep 4.
Although functions for the steroid hormone ecdysone during Drosophila metamorphosis have been well established, roles for the embryonic ecdysone pulse remain poorly understood. We show that the EcR-USP ecdysone receptor is first activated in the extraembryonic amnioserosa, implicating this tissue as a source of active ecdysteroids in the early embryo. Ecdysone signaling is required for germ band retraction and head involution, morphogenetic movements that shape the first instar larva. This mechanism for coordinating morphogenesis during Drosophila embryonic development parallels the role of ecdysone during metamorphosis. It also provides an intriguing parallel with the role of mammalian extraembryonic tissues as a critical source of steroid hormones during embryonic development.
尽管类固醇激素蜕皮激素在果蝇变态过程中的功能已得到充分确立，但胚胎蜕皮激素脉冲的作用仍知之甚少。我们发现，EcR-USP蜕皮激素受体首先在胚外羊膜浆膜中被激活，这表明该组织是早期胚胎中活性蜕皮甾类的来源。蜕皮激素信号传导是胚带收缩和头部内卷所必需的，这两种形态发生运动塑造了一龄幼虫。果蝇胚胎发育过程中这种协调形态发生的机制与蜕皮激素在变态过程中的作用相似。它还与哺乳动物胚外组织在胚胎发育过程中作为类固醇激素的关键来源的作用有着有趣的相似之处。
