The Roles of Calcium Pulses, Waves, and Gradients in Early Development

本课程将探讨细胞内游离钙脉冲、波动和梯度在海鞘卵子和细胞黏菌早期发育中的作用。该提案特别涉及钙在这些系统中建立发育模式的作用，即在Ciona或Phallusia卵中的卵质分离；以及在网柄柄菌中建立前柄和孢子细胞的模式。这些探索将主要通过三种方式进行：1)借助光蛋白Aequorin和成像光子探测器直接可视化游离钙的变化和模式。2)通过注入新合成的弱钙缓冲液等多种手段，特别干扰(从而研究)这些钙模式的作用。3)使用新开发的钙离子特异性细胞外振动电极，检测有助于产生这些游离钙模式的跨细胞钙电流。早期胚胎的发育是由位于未受精卵和新受精卵不同区域的信息分子的梯度控制的。建立这一信息的主要组成部分之一似乎与钙分布本身有关。贾菲博士将使用最初在他的实验室开发的试剂和探测器直接测试这一想法。

The roles of free cytosolic calcium pulses, waves, and gradients in the early development of ascidian eggs as well as of cellular slime molds will be explored. The proposal is particularly concerned with the roles of calcium in establishing developmental pattern in these systems, i.e., in ooplasmic segregation in the Ciona or Phallusia egg; and in establishing a pattern of prestalk and spore cells in Dictyostelium. These explorations will be carried out in three main ways: 1) Directly visualize free calcium changes and patterns with the aid of the photoprotein aequorin and an imaging photon detector. 2) Specifically perturb (and thus study the roles) of these calcium patterns with various means which will include the injection of newly synthesized weak calcium buffers. 3) Examine the transcellular calcium currents which help produce these free calcium patterns by using a newly developed calcium-specific vibrating extracellular electrode. %%% The development of an early embryo is controlled by gradients of informational molecules localized in different regions of the unfertilized and newly fertilized egg. One of the major components involved in establishing this information appears to be coupled to calcium distribution itself. Dr. Jaffe will test this idea directly using reagents and detectors originally developed in his laboratory.