Department of Zoology, Michigan State University, East Lansing, Michigan 48824, USA.
Dev Biol. 2011 Sep 15;357(2):318-25. doi: 10.1016/j.ydbio.2011.07.002. Epub 2011 Jul 12.
The developmental mechanisms by which growth is coordinated among developing organs are largely unknown and yet are essential to generate a correctly proportioned adult. In particular, such coordinating mechanisms must be able to accommodate perturbations in the growth of individual organs caused by environmental or developmental stress. By autonomously slowing the growth of the developing wing discs within Drosophila larvae, we show that growing organs are able to signal localized growth perturbation to the other organs in the body and slow their growth also. Growth rate is so tightly coordinated among organs that they all show approximately the same reduction in growth rate as the developing wings, thereby maintaining their correct size relationship relative to one another throughout development. Further, we show that the systemic growth effects of localized growth-perturbation are mediated by ecdysone. Application of ecdysone to larvae with growth-perturbed wing discs rescues the growth rate of other organs in the body, indicating that ecdysone is limiting for their growth, and disrupts the coordination of their growth with growth of the wing discs. Collectively our data demonstrate the existence of a novel growth-coordinating mechanism in Drosophila that synchronizes growth among organs in response to localized growth perturbation.
生长在不同器官间的协调机制在很大程度上是未知的，但对于生成一个比例正确的成年人来说是必不可少的。特别是，这种协调机制必须能够适应由于环境或发育压力而导致的单个器官生长的波动。通过自主减缓果蝇幼虫中正在发育的翅膀盘的生长，我们发现正在生长的器官能够向体内的其他器官发出局部生长扰动的信号，并减缓它们的生长速度。器官之间的生长速度如此紧密地协调，以至于它们的生长速度都与发育中的翅膀大致相同，从而在整个发育过程中保持它们彼此之间的正确大小关系。此外，我们还表明，局部生长扰动的系统性生长效应是由蜕皮激素介导的。将蜕皮激素应用于生长受到翅膀盘干扰的幼虫中，可以挽救体内其他器官的生长速度，这表明蜕皮激素限制了它们的生长，并破坏了它们与翅膀盘生长的协调。总的来说，我们的数据表明，在果蝇中存在一种新的生长协调机制，它可以响应局部生长扰动来协调器官间的生长。
