Macronuclear Development in Euplotes Crassus

提出的实验旨在了解染色质结构变化如何影响宏核发育过程中的DNA重排，包括以下内容。主要组蛋白和非组蛋白的复制、转录和出现的时间将通过标记研究来确定。染色质蛋白的合成和沉积在发展中的大核相关的切除将被确定。与Tec切除的关系将通过核酸酶消化来确定Tec元件染色质结构的改变。Tec元素的染色体外环状形式将被纯化为染色质，以确定参与切除的蛋白质是否仍然相关。特异的非核小体蛋白相互作用将通过足迹进一步鉴定。纤毛原生动物含有两种类型的细胞核，微核作为转录惰性生殖系核和大核转录指导细胞功能。在纤毛虫生命周期的性阶段，多种DNA重排和DNA加工事件参与了微核基因组从微核基因组形成的过程。该项目的目标是了解染色质结构变化如何影响宏核发育过程中的DNA重排。＊＊＊

Jahn 9319009 The proposed experiments aim to understand how chromatin structural changes influence in DNA rearrangements during macronuclear development and include the following. The timing of replication, transcription and appearance of major histone and non-histone proteins will be determined by labeling studies. Chromatin proteins whose synthesis and deposition in the developing macronucleus correlate with excision will be identified. Relationships to Tec excision will be determined by nuclease digestion to identify alterations in the Tec element chromatin structure. The extrachromosomal circular forms of Tec elements will be purified as chromatin to determine whether proteins involved in excision remain associated. Specific non-nucleosomal protein interactions will be further identified by footprinting. %%% Ciliated protozoa contain two types of nuclei, the micronucleus which serves as a transcriptionally inert germline nucleus and the macronucleus which transcriptionally directs cell functions. A variety of DNA rearrangements and DNA processing events are involved in the formation of the macronuclear genome from the micronuclear genome during the sexual phase of the ciliate life cycle. This project has as its goal an understanding of how chromatin structural changes influence the DNA rearrangements during macronuclear development. ***