RUI: The Gene Stream II: From Sequence to Cell Function

知识价值。四膜虫是自然界中一种罕见的单细胞生物。作为纤毛虫，单细胞四膜虫有两个根本不同的细胞核，而不是一个。较大的大核积极表达并负责驱动细胞的日常活动。较小的微核通常是沉默的，充当细胞的遗传档案，存储每个基因的两个副本，当生物体与交配伴侣进行核交换时，这些基因最终将被共享。在这方面，像四膜虫这样的纤毛虫类似于多细胞胚胎，其中某些细胞分化成一个发育中的有机体的身体（体细胞），而其他细胞被保留下来成为生殖系的一部分（未来的卵子或精子）。值得注意的是，研究人员发现，许多有助于区分动物生殖系和体细胞的相同蛋白质，可能在区分纤毛虫生殖系微核和体细胞巨核方面发挥类似的作用。因此，在了解生殖系和四膜虫体细胞的蛋白质方面获得的信息将在理解更大、更复杂的多细胞系统中发生的分化方面具有广泛的应用。这里的项目是探索同体的结构和功能，同体是在交配的四膜虫中发现的一种小的细胞内结构，类似于动物胚胎中的p颗粒，已被证明可以容纳导致基因组修饰的蛋白质，从而区分体细胞和种系。研究人员还在探索一种独特的细胞-细胞连接，即核交换连接，它允许交配细胞通过一个显著的细胞间窗口相互交换细胞核。本研究汇集了三个学科：蛋白质组学（从细胞器的蛋白质成分中鉴定基因），分子遗传学（通过靶向突变敲除基因，并用荧光标记标记基因产物，以便在活细胞中进行显微镜观察）和生物信息学，从已发表的四膜虫基因组中学习基因，并通过计算机辅助搜索所有已发表的基因组。更广泛的影响圣奥拉夫学院的调查人员研究项目是专门为本科生研究人员设计的培训工具。基因流允许学生创建跨学科的持续研究项目，从化学到生物学和计算机科学，同时保持一个集中的研究目标，即发现活细胞中特定基因所起的作用。这个跨学科的项目使本科生接触到科学家在日益合作的现代研究环境中使用的各种实验方法和实验室工具。基因流还为我们的本科生提供了前往其他大学实验室进行专业培训的机会，以及参加国家和地区会议的机会，在那里他们展示自己的工作，并收到研究生、博士后和研究生机构的pi的反馈。研究人员正在实验室里与学生一起开展工作，他们创建了一个研讨会，为在纤毛虫分子生物学领域工作的学院和大学教授提供了一个夏季论坛，以分享专业知识，同时编织一个校际研究合作。

Intellectual merit. Tetrahymena is an unusual organism that exists in nature as a single cell. As a ciliate, the unicellular Tetrahymena possesses not one, but two nuclei that are fundamentally different. The larger macronucleus is actively expressed and responsible for driving the daily activities of the cell. The smaller micronucleus is usually silent, and serves as a genetic archive for the cell, storing two copies of every gene that will be ultimately shared when the organism engages in nuclear exchange with a mating partner. In this regard, ciliates such as Tetrahymena resemble multicellular embryos, in which certain cells differentiate into the body (soma) of a developing organism while other cells are set aside to become a part of the germ line (future eggs or sperm). Remarkably, researchers have found that many of the same proteins that help distinguish the germline of an animal from the soma may play a similar role in distinguishing the germline micronucleus of a ciliate from the somatic macronucleus. Therefore, information gained in understanding the proteins of the germline and the soma of Tetrahymena will have broad scale applications in understanding differentiation as it occurs in larger, more complex multicellular systems. The project here is to explore the structure and function of the conjusome, a small intracellular structure found in mating Tetrahymena that resembles the P-granules in animal embryos that have been shown to house proteins that bring about genome modifications leading to the distinction between soma and germline. The investigators are also exploring a unique cell-cell junction, the nuclear exchange junction, that allows mating cells to trade nuclei with one another through a remarkable intercellular window. Three disciplines are brought together in this study: proteomics (the identification of genes from the protein constituents of an organelle), molecular genetics (knocking out genes by targeted mutation, and tagging gene products with fluorescent markers for microscopic observation in living cells), and bio-informatics, learning about a gene from the published Tetrahymena genome and through computer assisted searches of all the published genomes.Broader Impact The investigators' research program at St. Olaf College is specifically designed as a training vehicle for undergraduate researchers. The Gene Stream allows students to create sustained research projects that cross disciplines, from chemistry to biology and computer science, while maintaining a focused research goal, namely discovering the roles played by specific genes within a living cell. This cross-disciplinary program exposes undergraduates to the variety of experimental approaches and laboratory tools that scientists employ in the increasingly collaborative environment of modern research. The Gene Stream also provides our undergraduates with opportunities to travel to other University laboratories for specialized training as well as national and regional meetings where they present their work and receive feedback from graduate students, postdocs and PIs from graduate institutions. The investigators are extending their work with students in the laboratory by creating a workshop that provides a summer forum for college and university professors working in the field of Ciliate molecular biology to share expertise while weaving together an inter-collegiate research collaboration.