LOCALIZED MRNA IN XENOPUS DEVELOPMENT

一个关于控制发展的长期理论 从受精卵到胚胎的过程是母体分子， 是受精前存在于卵子中的分子， 早期胚胎发生的事件。 通过母体定位 卵的特定区域，这些细胞是由 卵子的分裂会遗传不同的母体分子， 赋予他们独特的身份， 发展能力。 理解的职能作用 局部化的母体分子被认为是理解 控制早期发展。 有许多实验结果证实了 局部母体分子 最近有一类 已经鉴定了定位分子，信使RNA（mRNA 克隆。 这些最近的成功鼓励了对 定位mRNA作为理解 局部母体分子的作用。 实验系统 是一种叫做非洲爪蟾的青蛙。 在将要解决的问题中， 编码这些mRNA的基因的转录受到控制。 基因的主要序列将被检查， 相似性和差异性，以及假定的转录 将在卵母细胞发育过程中研究控制区域， 胚胎发生，以发现影响它们的因素， 激活和抑制。 这些研究应该会带来更好的 了解是什么调节母体和胚胎 转录。 mRNA通过翻译成蛋白质发挥作用。 的 蛋白质的时间外观和胚胎定位 也将检测定位mRNA的产物。 这些 蛋白质将使用识别它们的抗体来可视化， 他们的功能研究都阐明了他们的相似之处， 通过结构分析已知功能的蛋白， 将其引入发育中的胚胎中以检查其影响 当错误定位，突变，或在更大的丰度比 通常存在于胚胎中。 最后，只有少数定位的mRNA被分离出来， 约会 对这一母性阶层新成员的隔离 分子，来自卵子和胚胎的不同区域， 必要 这些新的分子将被识别和分离， 母体RNA衍生的cDNA λ的差异筛选 图书馆.

One long standing theory concerning the control of development from fertilized egg into embryo is that maternal molecules, that is molecules present in the egg prior to fertilization, direct the events of early embryogenesis. By localization of maternal molecules to specific regions of the egg, the cells that result from cleavage of the egg inherit different sets of maternal molecules, giving them a unique identity and endowing them with defined developmental capacity. Understanding the functional role of localized maternal molecules is viewed as a way to understand control of early development. There are many experimental results confirming the existence of localized maternal molecules. Recently members of one class of localized molecule, messenger RNA (mRNA) have been identified and cloned. These recent successes encourages the study of localized mRNA as a starting point towards understanding the role of localized maternal molecules. The experimental system that will be used is the frog, Xenopus laevis. Among the questions that will be addressed, is the way the transcription of the genes encoding these mRNA are controlled. The primary sequence of the genes will be examined for similarities and differences, and the putative transcriptional control regions will be studied during oocyte development and embryogenesis to discover the factor that influence both their activation and repression. These studies should lead to a better understanding of what regulates maternal and embryonic transcription. mRNA exert their role by being translated into proteins. The temporal appearance, and embryonic localization of the protein products of the localized mRNAs will also be examined. These proteins will be visualized using antibodies that recognize them, their functions studied both by elucidating their similarity to proteins of known function by structural analysis, and by introduction back into developing embryos to examine their affect when mislocalized, mutated, or in greater abundance than normally found in the embryo. Finally, only a handful of localized mRNAs have been isolated to date. The isolation of new members of this class of maternal molecule, from different regions of the egg and embryo is necessary. These new molecules will be identified and isolated by differential screening of maternal RNA derived cDNA lambda libraries.