MRI: Acquisition of a Fluorescence Stereomicroscope to Enhance Undergraduate Research at Colorado College

这笔重大研究仪器拨款支持购买荧光立体显微镜和成像系统，以加强科罗拉多学院生物系Darrell J.Killian博士和Nancy N.Huang博士的研究计划。在活的模型生物中实时显示荧光分子已经成为一项不可或缺的技术，因为它允许直接观察和记录基因活性的变化，蛋白质在细胞内的定位，以及细胞和组织发育过程中的跟踪。生物学中的一个重要问题是，基因活动的变化如何决定特定性别的发育。基利安实验室感兴趣的是识别和表征影响广受欢迎的模式生物--秀丽线虫(C.elegans)--性别特异性发育的基因。线虫种群含有雄性和两性，它们具有明显的形态差异。然而，神经系统中不同性别的细胞类型的差异并不容易看到。性别特异性细胞类型的荧光标记已经成为识别性别特异性发育缺陷的强大而敏感的工具。已经分离出形态正常的雄性或两性的突变体，但其神经元通常只在异性中发现。识别受这些突变影响的基因及其随后的特征将为性别特异性发育的遗传基础提供新的见解。荧光立体显微镜和成像对于观察和记录在体使用性别特定细胞类型的荧光标记检测到的性缺陷是必不可少的。黄实验室感兴趣的是细胞身份或细胞命运规范是如何建立的。MEX-3是一种在线虫胚胎发育过程中在细胞命运规范中发挥重要作用的蛋白质。MEX-3蛋白最初存在于胚胎的所有细胞中，但在四细胞期时从后部细胞中消失。MEX-3分布的这种变化是建立胚胎前后轴所必需的，因此了解MEX-3在胚胎中的定位是很重要的。初步证据表明，MEX-3被主动降解的方式依赖于两种不同类型的蛋白质修饰，即磷酸化和泛素化。确定MEX-3蛋白中这些修饰的特定位置和识别调控这些修饰的基因是非常有意义的。荧光显微镜将使体内研究荧光标记的MEX-3的稳定性，当MEX-3的特定位置发生突变或当线虫基因组中的其他基因被扰乱时。科罗拉多学院是美国落基山地区唯一一所全国排名的文科学院，从美国各地和国际上招收约2000名本科生。生物系致力于与本科生合作开展原创研究，荧光显微镜和成像系统将为每年约6-10名在基利安和黄实验室工作的本科生提供重要的研究和培训机会。此外，生物学课程中的许多课程都以研究性实验室体验为特色。有这种经历的学生最有能力应对他们可能面临的任何研究生挑战。这些设备将加强和改进与几门课程相关的实验室活动、演示和实验，每年将影响大约200名本科生。成像系统将是一种特别有价值的教学工具，因为它将使教师和一组学生能够在计算机显示器上同时观察相同的样本。生物系还在学院发挥着强大的服务作用，提供非专业课程，培养学生对基础生物学研究的强烈欣赏，并使学生能够就许多生物学领域的热门话题做出明智的决定和意见，如干细胞研究、基因治疗、转基因生物和环境问题。荧光立体显微镜将为非专业学生提供独特和令人兴奋的机会，让他们第一手观察尖端科学。最后，科罗拉多学院积极寻求增强校园的多样性，并提供最先进的仪器，如荧光立体显微镜和成像系统，这将有助于吸引代表不足的少数族裔和妇女参与生物学研究。

This Major Research Instrumentation grant supports the acquisition of a fluorescence stereomicroscopeand an imaging system to enhance the research programs of Dr. Darrell J. Killian and Dr. Nancy N.Huang in the Biology Department at Colorado College. The real-time visualization of fluorescentmolecules in living model organisms has become an indispensable technique because it allows the directobservation and documentation of changes in gene activity, the localization of proteins within a cell, andthe tracking of cells and tissues during development. An important question in biology is how changes ingene activity determine sex-specific development. The Killian Lab is interested in the identification andcharacterization of genes that affect sex-specific development in the popular model organismCaenorhabditis elegans (C. elegans), a soil-dwelling roundworm. C. elegans populations contain malesand hermaphrodites, which have some obvious morphological differences. However, sex-specific celltype differences in the nervous system are not easy to see. Fluorescent markers for sex-specific celltypes have emerged as powerful and sensitive tools for the identification of defects in sex-specificdevelopment. Mutants have been isolated that are morphologically normal males or hermaphrodites, butwith neurons that are normally only found in the opposite sex. The identification of the genes affected bythese mutations and their subsequent characterization will provide new insights into the genetic basis ofsex-specific development. Fluorescence stereomicroscopy and imaging are essential for the observationand documentation of sexual defects that are detected in vivo using fluorescent markers for sex-specificcell types. The Huang Lab is interested in how cellular identity, or cell fate specification, is established.MEX-3 is a protein that plays an important role in cell fate specification during C. elegans embryonicdevelopment. The MEX-3 protein is initially present in all cells of the embryo but becomes depleted fromthe posterior cells by the four-cell stage. This change in MEX-3 distribution is required for theestablishment of the anterior/posterior axis of the embryo, thus it is important to understand how MEX-3 islocalized in the embryo. Preliminary evidence suggests that MEX-3 is actively degraded in a manner thatis dependent upon two different types of protein modifications termed phosphorylation and ubiquitination.The identification of the specific sites of these modifications within the MEX-3 protein and theidentification of genes that regulate these modifications are of great interest. Fluorescence microscopywill enable an in vivo study of the stability of fluorescently tagged MEX-3 when specific sites in MEX-3 aremutated or when other genes in the C. elegans genome are disrupted.Colorado College is the only nationally ranked liberal arts college in the Rocky Mountain region of theUnited States and enrolls approximately 2000 undergraduates from all over the United States andinternationally. The Biology Department has a strong commitment to conducting original research withundergraduate collaboration and the fluorescence microscope and imaging system will provide importantresearch and training opportunities for approximately 6-10 undergraduates working in the Killian andHuang labs each year. In addition, many courses in the Biology curriculum feature inquiry-basedresearch lab experiences. Students with such experiences are best equipped to handle any postgraduatechallenges that they might face. The equipment will augment and improve laboratory activities,demonstrations, and experiments associated with several courses and will impact approximately 200undergraduates per year. The imaging system will be a particularly valuable teaching tool because it willenable the instructor and a group of students to simultaneously observe the same sample on a computermonitor. The Biology Department also plays a strong service role in the college by offering non-majorscourses that foster a strong appreciation for basic biology research and empower students to makeinformed decisions and opinions on many popular topics in biology such as stem cell research, genetherapy, genetically modified organisms, and environmental issues. The fluorescence stereomicroscopewill provide non-majors with unique and exciting opportunities to observe cutting-edge science first-hand.Finally, Colorado College actively seeks to enhance diversity on campus and the availability of state-ofthe-art instrumentation, such as a fluorescence stereomicroscope and imaging system, will help attractunderrepresented minorities and women to participate in biology research.