RUI: Genetic Analysis of Conjugation in Tetrahymena

嗜热四膜虫（Tetrahymena thermophila）是一种淡水纤毛虫原生生物，特别适合于分析与细胞分裂周期和接合（有性生殖）相关的核和染色体事件。 纤毛虫在有丝分裂过程中表现出无与伦比的丰富的发育里程碑，凭借精确控制的增殖和形成纤毛口腔器的细胞皮层中的基体图案。 这种皮层程序与核分裂和胞质分裂相结合，并在细胞分裂期间提供了一个易于可视化的、丰富详细的发育事件“时钟”。这个发展计划提供了独特的机会，了解核皮质相互作用的遗传控制，通过这个细胞周期占主导地位的景观调节细胞的进展。三个功能推荐该系统用于发育分析：丰富的发育标志，携带和表达具有致死表型的突变的能力，以及研究靶向有丝分裂和减数分裂机制而不影响细胞活力的突变的能力。 本项目的目标有三个：1）构建和筛选一个“反义”文库以寻找与接合发育相关的基因; 2）对“fenestrin”和其他与原核交换连接相关的蛋白质进行生物化学研究; 3）揭示“星星”细胞系中与接合发育阻滞相关的发育“检查点”的细胞遗传学基础。涉及这3种分析方法的工作将揭示纤毛虫四膜虫嗜热性发育的遗传基础及其与细胞分裂周期的整合。 该项目还将有助于将细胞分裂周期中细胞表面发生的事件与细胞核内发生的事件联系起来，同时为本科生提供上级研究培训体验。

Tetrahymena thermophila, a freshwater ciliated protist, is uniquely well suited for ana-lysis of nuclear and chromosomal events associated with both the cell division cycle and conjugation (sexual reproduction). Ciliates exhibit an unparalleled richness of developmental landmarks during mitosis by virtue of the precisely controlled proliferation and patterning of basal bodies that form the ciliated oral apparatus in the cell cortex. This cortical program is coupled to both nuclear division and cytokinesis and provides an easily visualized, richly detailed "clock" of developmental events during cell division. This developmental program offers unique opportunities for understanding the genetic control of nuclear-cortical interactions that regulate a cell's progress through this cell-cycle dominated landscape. Three features recommend this system for developmental analysis: a wealth of developmental landmarks, the ability to carry and express mutations with lethal phenotypes, and the ability to study mutations that target both mitotic and meiotic mechanisms without affecting cell viability. The goals of this project are three fold: 1) Build and screen an "antisense" library to search for genes involved in conjugal development, 2) Launch a biochemical investigation into "fenestrin" and other proteins associated with the pronuclear exchange junction, 3) Uncover the cytogenetic basis of the developmental "checkpoint" associated with conjugal arrest in "star"-cell lines that abort normal conjugal development. Work involving these 3 methods of analysis will shed light on the genetic basis of sexual development in the ciliate Tetrahymena thermophila and its integration with the cell division cycle. This project will also help to link events occurring at the cell surface with events occurring within the cell's nucleus during the cell division cycle while providing a superior research training experience for undergraduate students.