Kapali George P, Callier Viviane, Gascoigne Samuel J L, Harrison Jon F, Shingleton Alexander W
Department of Biological Sciences, University of Illinois Chicago, 840 West Taylor Street, Chicago, IL, 60607, USA.
School of Life Sciences, Arizona State University, Tempe, AZ, 85287-4501, USA.
Sci Rep. 2022 Mar 18;12(1):4730. doi: 10.1038/s41598-022-08563-9.
In almost all animals, physiologically low oxygen (hypoxia) during development slows growth and reduces adult body size. The developmental mechanisms that determine growth under hypoxic conditions are, however, poorly understood. Here we show that the growth and body size response to moderate hypoxia (10% O) in Drosophila melanogaster is systemically regulated via the steroid hormone ecdysone. Hypoxia increases level of circulating ecdysone and inhibition of ecdysone synthesis ameliorates the negative effect of low oxygen on growth. We also show that the effect of ecdysone on growth under hypoxia is through suppression of the insulin/IGF-signaling pathway, via increased expression of the insulin-binding protein Imp-L2. These data indicate that growth suppression in hypoxic Drosophila larvae is accomplished by a systemic endocrine mechanism that overlaps with the mechanism that slows growth at low nutrition. This suggests the existence of growth-regulatory mechanisms that respond to general environmental perturbation rather than individual environmental factors.
在几乎所有动物中，发育过程中生理上的低氧（缺氧）会减缓生长速度并减小成年后的体型。然而，对于在缺氧条件下决定生长的发育机制，我们却知之甚少。在此，我们表明，果蝇对中度缺氧（10%氧气）的生长和体型反应是通过类固醇激素蜕皮激素进行系统调节的。缺氧会增加循环中蜕皮激素的水平，而抑制蜕皮激素合成则可改善低氧对生长的负面影响。我们还表明，蜕皮激素在缺氧条件下对生长的影响是通过抑制胰岛素/胰岛素样生长因子信号通路实现的，其机制是增加胰岛素结合蛋白Imp-L2的表达。这些数据表明，缺氧果蝇幼虫的生长抑制是通过一种系统内分泌机制完成的，该机制与低营养条件下减缓生长的机制重叠。这表明存在着对一般环境扰动而非个别环境因素作出反应的生长调节机制。
