Translational Control of Growth and Apoptosis in C. Elegans Development by Initiation Factor Isoforms

新的基因表达是细胞开始生长和分裂(增殖)或改变其命运(分化)所必需的。卵子和精子(配子)的发育同样涉及基因表达和分化的关键时期。早期细胞分裂，然后分化为精子或卵母细胞。基因转录在配子发生早期是活跃的，但随着细胞进入减数分裂，基因转录变得沉默，因此在增殖期储存的mRNAs成为产生新蛋白质的唯一手段。在卵母细胞、精母细胞或胚胎中，发育重要的mRNAs被翻译成核糖体上的蛋白质，而新的蛋白质要么指导继续分化，要么指导细胞死亡(细胞凋亡)。这个研究项目的重点是被称为eIF4因子的蛋白质，它们联系着要翻译的mRNAs，作为招募它们进入蛋白质合成机制的第一步。具体地说，将研究在配子和胚胎中导致新蛋白质合成的eIF4因子的活性。动物模型系统，如土栖线虫，秀丽线虫，在这项研究中是必不可少的，因为它们通常比人类胚胎更简单。线虫胚胎从受精卵发育成有组织的多细胞胚胎，发育方式与高等动物非常相似。幸运的是，这些蠕虫的身体结构要简单得多，只由几块肌肉、神经元、消化和生殖器官组成。在目前的背景下，更重要的是，在这个简单的模型系统中，所需的关键基因非常相似。由于蛋白质合成机制在动物中非常保守，使用线虫的研究结果将有助于揭示脊椎动物配子和胚胎中的基因表达，而这些方法在这些领域是不可行或不实用的。广泛的影响和教育效益：该项目直接影响到在凯珀博士的实验室完成博士论文研究的少数族裔和女性研究生的教育，以及ECU生物和化学系的硕士和本科生的教育。与过去的授权期一样，该项目还包括合作者和其他大学和高中的学生，他们对发育过程中的分子基因表达感兴趣。这项研究利用了该实验室在mRNA翻译的生物化学方面的经验，并为年轻科学家提供了广泛的分子技术、遗传学和转基因方面的实验室培训。这些学生发现线虫系统比哺乳动物系统更容易驯化，而且在智力上更容易接近。他们从直接参与新发现中获得最大的教育好处，以及有机会在科学期刊上展示他们的发现和发表他们的成就。近年来，参与该项目的几名学生已经在生物技术行业找到了职位，或进入了研究生研究/医学专业学术课程。

New gene expression is required for cells to begin to grow and divide (proliferation) or to alter their fate (differentiation). The development of egg and sperm (gametes) likewise involves crucial periods of gene expression and differentiation. Early cells divide and then differentiate into either sperm or oocytes. Gene transcription is active early in gametogenesis, but becomes silenced as cells enter meiosis, and thus mRNAs that have been stored during the proliferative phase become the sole means to produce new proteins. Developmentally important mRNAs become translated into protein on ribosomes in the oocyte, spermatocyte or embryo, and the new proteins direct either continued differentiation or cell death (apoptosis). This research project is focused on proteins called eIF4 factors, which contact the mRNAs to be translated as the first step in recruiting them to the protein synthesis machinery. Specifically, the activities of eIF4 factors that lead to new protein synthesis in gametes and embryos will be investigated. Animal model systems such as the soil-dwelling nematode worm, Caenorhabditis elegans, are essential in this research because they are generally simpler than human embryos. The C. elegans embryo develops from a fertilized egg to an organized multi-cellular embryo in a manner very similar to that of higher animals. Fortunately these worms have a far simpler body plan made up of just a few muscles, neurons, digestive and reproductive organs. More importantly in the present context, the critical genes required are very similar in this simple model system. Because protein synthesis mechanisms are well conserved in animals, research findings using C. elegans will shed light on gene expression in vertebrate gametes and embryos, where such methods are not feasible or practical.Broader Impact and Educational Benefit: This project directly impacts the education of a minority and a female graduate student who are completing Ph.D. thesis research in Dr. Keiper's laboratory, as well as Masters and undergraduate students from ECU's Biology and Chemistry departments. As in the past granting period, the project also involves collaborators and students from other universities and high schools with an interest in molecular gene expression during development. The research capitalizes on the lab's experience in the biochemistry of mRNA translation and provides broad laboratory training in molecular techniques, genetics and transgenesis to young scientists. These students find the C. elegans system both tractable and significantly more accessible intellectually than mammalian systems. They receive the greatest educational benefit from first-hand involvement in new discoveries as well as opportunities to present their findings and publish their accomplishments in scientific journals. In recent years, several students who participated in this project have taken positions in the biotechnology industry or entered graduate research/medical professional academic programs.