RUI: Studies on the Cell Physiology of Insect Ovarian Follicles

在许多动物中，早期胚胎发育是由受精前卵子中的分子控制的。最著名的例子是在昆虫果蝇和脊椎动物两栖动物非洲爪哇中发现的“头部因子”，其中RNA信息(母体信息)位于发育中的卵子的前端。当受精后被激活时，它们在那个局部区域产生控制蛋白，这些控制蛋白前移导致头部形成。然而，这些和类似的“信息”的本地化需要优先水平的控制因素，这些因素在卵子本身的形成中起作用，确保它为母体信息本地化提供适当的环境。在大多数动物中，这涉及到卵泡的形成，该卵泡由一个卵母细胞和一个或多个兄弟姐妹哺育细胞组成，后者是早期发育过程中使用的大多数RNA的合成地点。这项计划的目标是将持续进展的研究延长27年，重点在于阐明和理解调控卵子形成(卵子发生)的生理机制，这反过来又提供了母体信息可以插入其中的框架。特别令人感兴趣的是，内部离子钙离子参与了调控过程。本研究利用显微注射、双向凝胶电泳法和细胞内微电极技术，探讨了细胞内钙电流与可能调节细胞功能的带电胞浆蛋白分布之间的关系。该提案的很大一部分是基于扩展到果蝇的概念，最初是用天牛透明蛾的卵来展示的，这种蛾经常被用作研究模型。果蝇的具体目标包括测量体内离子活性和离子泵，以更好地描述这种生物在研究中经常使用的卵母细胞生理学。此外，还建议确定离子生理变化对内源性胞浆蛋白分布的影响以及对卵母细胞核尿苷结合活性的影响。总体而言，这项研究试图增加对产卵调节机制的了解，期望这些机制不仅适用于昆虫，也适用于脊椎动物物种。

In many animals, early embryonic development is controlled by molecules positioned in the egg before fertilization. The best known examples are the "head factors" found in the insect Drosophila, and the vertebrate amphibian Xenopus, where RNA messages (maternal messages) are positioned at the anterior end of the developing egg. When activated after fertilization, they produce control proteins in that localized region, which anteriorization resulting in head formation. However, localization of these and similar "messages" require a prior level of control factors which operate in the formation of the egg itself, insuring that it provides the proper milieu for maternal message localization. In most animals this involves the formation of an ovarian follicle consisting of an oocyte and one or more sibling nurse cells, the latter being the site of synthesis for most of the RNA used during early development.The objectives of this proposal, which extends research in continual progress for 27 years, focus on illuminating and understanding the physiological mechanisms which regulate and control egg formation (oogenesis), which in turn provide the framework into which the maternal messages can be inserted. Of particular interest is the involvement of internal ionic Ca2+ in the regulatory process. Using microinjection, two dimensional gel electrophoresis and intracellular microelectrodes, this research explores the relationship between an internal Ca2+ current and the distribution of charged cytosolic proteins which may regulate cell functions. Much of the proposal is based upon extending to Drosophila concepts originally demonstrated with eggs of Hyalophora cecropia, a moth which has frequently served as a research model. Specific objectives Drosophila include measurements of internal ion activities and ion pumps to better characterize the oocyte cell physiology of this organism so frequently used in research. In addition it is proposed to determine the effects of changed ion physiology upon the distribution of endogenous cytosolic proteins and upon uridine incorporating activity by the oocyte nucleus. Overall, this research seeks to increase understanding of the mechanisms which regulate egg production, with the expectation that they will apply not only to insects, but to vertebrate species as well.