Regulation of Photosynthesis During Nitrogen Fixation in a Filamentous Cyanobacterium (Biological Science)

将大气中的氮还原为氨， 固氮，被氧气抑制;因此，氧气释放 光合系统II和固氮不能共存。 一些 具有光系统II的丝状蓝细菌可以 分化细胞，称为异形胞，专门用于 固氮作用 许多结构和生化变化发生 在异形胞分化过程中，包括光系统的丧失 II（PSII）活性。 泰尔博士将研究 这一光系统的组成部分的失活， 异形胞分化 她会在异形胞中识别- 形成蓝藻PSII组分的基因， Western杂交和PSII的蛋白质组分 印迹，并将研究这些转录的调节 基因和这些蛋白质在异形胞期间的周转 分化 这些研究应提供关于 细胞机制使有机体能够 进化PSII来固氮。 Thiel博士将团队教授微生物学课程， 生物能量学，在研究生研讨会课程中讲课， 指导研究生的研究。 她也会给 正式研讨会，并就机会进行非正式讨论 通过妇女资源中心， 华盛顿大学。 本项目进一步促进了VPW计划的目标，即（1） 为妇女提供机会， 工程和科学的学科由NSF支持 （2）鼓励妇女从事科学事业， 通过提高女科学家的知名度， 以及受雇于工业、政府和学术界的工程师 机构职能体系 通过鼓励妇女参与 这是对国家未来的宝贵投资。 科学生命力

The reduction of atmospheric nitrogen to ammonia, termed nitrogen fixation, is inhibited by oxygen; hence, oxygen-evolving photosystem II and nitrogen fixation cannot coexist. Some of the filamentous cyanobacteria, which have photosystem II, can differentiate cells, called heterocysts, that are specialized for nitrogen fixation. Many structural and biochemical changes occur during heterocyst differentiation, including loss of photosystem II (PSII) activity. Dr. Thiel will study the mechanism of inactivation of the components of this photosystem during heterocyst differentiation. She will identify in a heterocyst- forming cyanobacterium the genes for PSII components by Southern hybridization and the protein components of PSII by Western blots, and will study the regulation of transcription of these genes and the turnover of these proteins during heterocyst differentiation. These studies should provide information on the cellular mechanisms that allow an organism that has oxygen evolving PSII to also fix nitrogen. Dr. Thiel will team teach courses in Microbiology and in Bioenergetics, give lectures in graduate seminar courses, and direct the research of graduate students. She will also give formal seminars and have informal discussions on opportunities for women in science through the Women's Resource Center at Washington University. This project furthers VPW program objectives which are (1) to provide opportunities for women to advance their careers in engineering and in the disciplines of science supported by NSF and (2) to encourage women to pursue careers in science and engineering by providing greater visibility for women scientists and engineers employed in industry, government, and academic institutions. By encouraging the participation of women in science, it is a valuable investment in the Nation's future scientific vitality.