Collaborative Project: Calcium in the Early Development of Hydrozoan

几种水螅类动物的卵和胚胎含有内源性钙指示剂，类似于水钙素。这些制剂为研究钙在早期发育中的作用提供了独特的机会。两个钙瞬变，一个在受精时，另一个在卵裂时，对正常发育至关重要。本项目将采用光子计数技术和图像增强视频显微镜方法来确定受精钙瞬态是否由钙波引起，并通过显微注射实验来确定参与其启动和传播的第二信使。水螅虫的细胞分裂是缓慢的，需要外部钙。光子计数、荧光染料注射和药物将用于研究细胞分裂过程中钙瞬态是如何被调节的。电压依赖性钙通道在受精后一小时左右开始发挥作用。这些通道在快速钙流入中起主要作用，但对导致通道功能开始的发育事件知之甚少。该项目将确定在水生动物中启动钙通道功能的因素。当卵裂期胚胎细胞质中钙含量上升时，钙同时从内质网转运到外部介质。该项目将确定介导这种钙外排的机制。

The eggs and embryos of several species of hydrozoans contain endogenous calcium indicators similar to aequorin. These preparations offer unique opportunities for studying the role of calcium in early development. Two calcium transients, one at fertilization, and another at cleavage, are crucial for normal development. This project will employ photon counting techniques and image intensified video microscopy methods to determine if the fertilization calcium transient is due to a calcium wave, and microinjection experiments to determine what second messengers participate in its initiation and propagation. Cytokinesis in hydrozoans is slow and requires external calcium. Photon counting, fluorescent dye injection, and drugs will be used to investigate how the calcium transient during cytokinesis is regulated. Voltage dependent calcium channels first become functional about one hour after fertilization. These channels play a major role in rapid calcium influx but very little is known about the developmental events that lead to the onset of channel function. This project will define the factors that are responsible for initiating calcium channel function in hydrozoans. When calcium rises in the cytosol of cleavage stage embryos, calcium is simultaneously transported from the endoplasmic reticulum to the external medium. This project will identify the mechanism that mediates this calcium efflux.