Early Events in Leech Embryogenesis

舌管蛭Helobdella triserialis的胚胎发育良好 适合研究早期发育中的细胞事件，因为它们 大，哈代，并包含可识别的细胞， 很多种实验操作。 这些胚胎表现出许多 在高等教育发展中具有普遍意义的现象 真核生物，包括细胞质决定簇， 细胞核和有丝分裂纺锤体，分裂和干细胞的不同阶段 分裂，外延，血统依赖和 位置依赖性命运决定和上皮相互作用。 的 这里提议的研究将采用各种技术，例如： 细胞谱系示踪剂、光敏染料、药物 放射化学;原位杂交;免疫组织化学;凝胶电泳 电泳;放射自显影;延时录像;低 光荧光显微镜。 从这些研究中，更详细的 描述各种发展过程和机制， 他们所经营的一切，都应该被创造出来。 此外，通过检查A 在同一物种中平行的发育过程的数量， 希望能对更高层次的机制有所了解， 基本的细胞和发育过程会相互作用。 例如，该项目的一部分将研究 在第一次分裂之前专门的细胞质结构域以及它们如何 可能会影响第一次分裂的对称性。 另一部分将 测试遗传RNA调节细胞变化的假设， 分裂模式 单个细胞如何获得特定命运的问题 在早期胚胎发育过程中是一个基本问题， 发育生物学 Weisblat博士，使用水蛭作为模型系统， 提出了一系列的实验来确定是什么影响细胞谱系 的胚胎。

Embryos of the glossiphoniid leech Helobdella triserialis are well suited for studying cellular events in early development, because they are large, hardy, and contain identifiable cells that are accessible for many sorts of experimental manipulations. These embryos exhibit many phenomena that are of general significance in the development of higher eukaryotes, including cytoplasmic determinants, directed movements of nuclei and mitotic spindles, distinct phases of cleavage and stem cell divisions, epiboly, separable instances of lineage dependent and position dependent fate determination, and epithelial interactions. The research proposed here would employ a variety of techniques, such as: the microinjectin of cell lineage tracers, photosensitizing dyes, drugs and radiochemicals; in situ hybridization; immunohistochemistry; gel electrophoresis; autoradiography; time lapse video recording; and low light fluorescence microscopy. From these studies, a more detailed description of various developmental processes and the mechanisms by which they operate should be generated. In addition, by examining a number of developmental processes in parallel in the same species, it is hoped that some understanding of the higher order mechanisms by which the basic cellular and developmental processes interact will emerge. For example, one part of this project would study the formation of specialized cytoplasmic domains prior to first cleavage and how they might influence the symmetry of the first cleavage. Another part would test the hypothesis that inherited RNAs regulate a change in cell division pattern. The question of how individual cells acquire their specific fates during early embryological development is a basic problem of developmental biology. Dr. Weisblat, using the leech as a model system, proposes a series of experiments to define what influences cell lineages of the embryo.