Collaborative Project: Calcium in the Early Development of Hydrozoans

合作项目：水螅动物早期发育中的钙

• 批准号: 8904333
• 负责人: Gary Freeman
• 金额: $ 8.49万
• 依托单位: University of Texas at Austin
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-08-01 至 1993-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8904333&HistoricalAwards=false
• 关键词: Collaborative; Project; Calcium; Early; Development

Drs. Ridgway and Freeman have recently discovered that the eggs and embryos of several species of hydrozoans contain endogenous calcium indicators similar to aequorin. Because the calcium indicators are natural, exist in high concentration, and emit light specifically in the presence of calcium, these preparations offer unique opportunities for studying the role of calcium in early development. They propose to investigate the mechanism that controls the appearance of calcium channels in the membrane at first cleavage in these organisms. These channels could play a role in establishing the anterior-posterior axis of the developing embryo. They will determine where and why these channels appear by using image intensification and image enhancement techniques in conjunction with microinjection of heterochronic cytoplasm. They have discovered that potassium depolarization of cleavage stage embryos leads to a bright flash which is due in part to calcium release from an internal store. They will investigate the mechanism that couples the calcium entry through the calcium channels to the calcium release internally. They will study the propagation of four sorts of calcium waves: 1. those due to IP3 diffusion in unfertilized eggs, 2. those that may occur at fertilization, 3. those due to depolarization of cleavage stage embryos, and 4. those accompanying metamorphosis. %%% The importance of calcium as a regulator of a number of cellular processes has been established. The question remains as to how is the level of calcium itself controlled. Drs. Ridgway and Freeman have developed a powerful model system in which to address this question. It exploits a naturally occurring luminescent protein found in hydrozoan embryos which emits light in the presence of calcium.

博士。 Ridgway和Freeman最近发现，几种水螅动物的卵和胚胎含有与水母发光蛋白类似的内源性钙指示剂。由于钙指示剂是天然的，以高浓度存在，并且在钙存在时特异性发光，因此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。他们提议研究控制这些生物体第一次分裂时膜中钙通道出现的机制。这些通道可以在建立发育胚胎的前后轴方面发挥作用。他们将通过使用图像增强和图像增强技术并结合异时细胞质的显微注射来确定这些通道出现的位置和原因。他们发现，卵裂期胚胎的钾去极化会导致明亮的闪光，部分原因是内部储存的钙释放。 他们将研究将钙通过钙通道进入与内部钙释放耦合的机制。他们将研究四种钙波的传播：1.未受精卵中IP3扩散引起的钙波，2.受精时可能发生的钙波，3.卵裂期胚胎去极化引起的钙波，4.伴随变态的钙波。 %%% 钙作为许多细胞过程调节剂的重要性已经得到证实。问题仍然是如何控制钙本身的水平。博士。 Ridgway 和 Freeman 开发了一个强大的模型系统来解决这个问题。它利用了水螅胚胎中发现的一种天然发光蛋白，该蛋白在钙存在的情况下会发光。