As a reaction-diffusion system strongly affected by temperature, early fly embryos surprisingly show highly reproducible and accurate developmental patterns during embryogenesis under temperature perturbations. To reveal the underlying temperature compensation mechanism, it is important to overcome the challenge in quantitative imaging on fly embryos under temperature perturbations. Inspired by microfluidics generating temperature steps on fly embryos, here we design a microfluidic device capable of ensuring the normal development of multiple fly embryos as well as achieving real-time temperature control and fast temperature switches for quantitative live imaging with a home-built two-photon microscope. We apply this system to quantify the temperature compensation of the morphogen Bicoid (Bcd) gradient in fly embryos. The length constant of the exponential Bcd gradient reaches the maximum at 25°C within the measured temperatures of 18-29°C and gradually adapts to the corresponding value at new temperatures upon a fast temperature switch. The relaxation time of such an adaptation becomes longer if the temperature is switched in a later developmental stage. This age-dependent temperature compensation could be explained if the traditional synthesis-diffusion-degradation model is extended to incorporate the dynamic change of the parameters controlling the formation of Bcd gradients.

中文翻译：

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使用快速 T 可调微流体装置量化 Bicoid 梯度的温度补偿


作为一个受温度强烈影响的反应扩散系统，早期果蝇胚胎在温度扰动下的胚胎发生过程中令人惊讶地表现出高度可重复和准确的发育模式。为了揭示潜在的温度补偿机制，克服温度扰动下果蝇胚胎定量成像的挑战非常重要。受微流控在果蝇胚胎上产生温度阶跃的启发，我们设计了一种微流控装置，能够确保多个果蝇胚胎的正常发育，并通过自制的两层微流控装置实现实时温度控制和快速温度切换，以实现定量实时成像。光子显微镜。我们应用该系统来量化果蝇胚胎中形态发生素 Bicoid (Bcd) 梯度的温度补偿。在18-29℃的测量温度范围内，指数Bcd梯度的长度常数在25℃时达到最大值，并在快速温度切换时逐渐适应新温度下的相应值。如果在发育后期改变温度，这种适应的弛豫时间会变得更长。如果将传统的合成-扩散-降解模型扩展到纳入控制 Bcd 梯度形成的参数的动态变化，则可以解释这种与年龄相关的温度补偿。