Ionic Mechanisms in the Initiation of Development

本研究的最终目的是深入了解 与卵子激活有关的机制 受精 重点将放在研究膜电位如何 当信号被转导到细胞内过程中时， 精子附着 电压钳位电生理测量 鸡蛋将与视频数字图像处理相结合， 电事件与（a）活细胞中的形态变化 难以以其他方式解决，（B）皮质肌动蛋白的出现 使用荧光标记的肌动蛋白或杀鬼笔菌素的细丝组装，和 (c)细胞内钙离子的变化和pH值，以及它们的定位 使用荧光指示剂和图像比率法进行改变。 膜电位在心肌细胞中的作用机制探讨 静息（-70mV）附近抑制精子进入（尽管 激活收益）将被追踪。 的可能性 抑制精子进入是负效应的结果， 将研究肌动蛋白丝组装的膜电位。 钱伯斯博士的实验室多年来一直活跃在 海胆受精卵激活的生理学研究。 在这些研究中选择海胆蛋是因为这个蛋（ 具有与人类卵子相同的大小和蛋黄含量）。 透明，大，易于大量使用， 实验室操作。 在更广泛的背景下，研究 旨在理解静止细胞， 在静止时，被激活以进行有丝分裂、细胞分裂和生长。

The ultimate objective of this research is to obtain insight into the mechanisms concerned in the activation of the egg during fertilization. Emphasis will be on investigating how membrane potential changes as signals are transduced into intracellular processes following sperm attachment. Electrophysiological measurements on voltage clamped eggs will be combined with video digital image processing to correlate electrical events with (a) morphological changes in the living cell difficult otherwise to resolve, (b) the occurrence of cortical actin filament assembly using fluorescently labeled actin or phallicidin, and (c) changes in intracellular ıCa2+! and pH and the localization of these changes using fluorescent indicators and image ratioing methods. Investigation of the mechanism whereby membrane potentials in the neighborhood of resting (-70mV) suppress sperm entry (although activation proceeds) will be pursued. The possibility that the suppression of sperm entry is the consequence of an effect of negative membrane potential on assembly of actin filaments will be investigated. Dr. Chambers's laboratory has been active for many years in the study of the physiology of sea urchin egg activation at fertilization. The sea urchin egg is chosen in these studies because this egg (which has about the same size and yolk content as the human egg) is transparent, large, readily available in large numbers and withstands laboratory manipulations. In a more general context, the research is directed toward understanding the mechanisms whereby a quiescent cell, at rest, is activated to undergo mitosis, cell division and growth.