Roles of clock genes in modulation of Drosophila oogenesis

A.项目总结：智力价值。生物钟是生理和行为节律的重要协调者。黑腹果蝇是研究生物钟机制的一个很好的模型，然而关于生物钟基因在果蝇生理学中的功能意义所知甚少。由Giebultowicz博士领导的研究小组证明，外围生物钟在生殖生理学中发挥着多种作用。最近的研究表明，两个基本的时钟基因，周期和永恒，参与调节女性的生育能力。令人惊讶的是，这些基因似乎不是生物钟的组成部分，而是体内平衡机制的一部分。提出了一种综合的生理和分子方法来研究这种新的健康相关表型。初步的数据导致了一种假设，即由周期和永恒编码的蛋白质是调节卵子产卵率的信号通路的一部分。这个假设将在一个分为四个目标的实验项目中进行检验。(1)将比较突变型和野生型雌性生殖生理学的几个方面，以确定突变型雌性是否改变了内分泌功能或其他生理参数，这些参数可能解释了它们在对富含蛋白质的饮食做出反应时未能增加卵子生成。(2)遗传学方法将用于确定高蛋白饮食的果蝇繁殖力的增加是否取决于卵巢或其他器官（如神经系统）的经期和无时间性基因的功能。(3)将在mRNA和蛋白水平上研究period和timeless的表达，以确定其是否受女性年龄和营养状况的影响。(4)生化工具将用于阐明周期和时间在女性繁殖力中的作用。这些目标的实现将得益于果蝇丰富的遗传信息和易于进行的分子操作，使其成为解剖多组分营养-繁殖力途径的理想系统。这些研究结果将有助于了解系统发育上保守的时钟基因在调节生殖力的遗传途径中的功能意义。更广泛的影响。这里概述的科学计划将促进几个教员、研究生和本科生之间的伙伴关系。建议的研究将提供充足的机会训练学生；来自科学界代表性不足群体的参与者将被积极招募到该项目中。生理、分子和基因实验的结合将使学生获得跨学科研究方法的经验。学生将在学术目标方面得到指导，并鼓励他们考虑从事科学事业。Giebultowicz博士在吸引本科女生参与她的研究并帮助她们选择科学作为职业方面有着出色的记录。PI还将研究活动整合到地区学校的科学教学中。她是美国国家科学基金会资助的俄勒冈州立大学K-12农村科学教育项目的共同负责人，指导本科生和研究生在俄勒冈州选定的农村学校教授科学。她还参与了中学女生的“冒险学习”项目，邀请学生到实验室进行小实验，提供动手学习科学的方法。利用NSF基金获得的研究成果将发表在同行评议的期刊上，研究重点将以公众可访问的格式发布在实验室网站上。

A. PROJECT SUMMARYIntellectual merit. Circadian clocks are important coordinators of physiological and behavioral rhythms. Drosophila melanogaster serves as an excellent model for investigating clock mechanisms, however little is known about the functional significance of clock genes in the fly physiology. The group led by Dr. Giebultowicz demonstrated that peripheral circadian clocks play multiple roles in reproductive physiology. Recent research revealed that two essential clock genes, period and timeless, are involved in the regulation of female fecundity. Surprisingly, these genes seem to act not as components of the circadian clock but as part of a homeostatic mechanism. An integrated physiological and molecular approach is proposed to investigate this novel fitness-related phenotype. Preliminary data led to a hypothesis that proteins encoded by period and timeless are part of the signaling pathway that modulates the rate of egg production. This hypothesis will be tested in an experimental program divided into four objectives. (1) Several aspects of reproductive physiology will be compared between mutant and wild-type females, to determine if mutant females have altered endocrine functions or other physiological parameters that may account for their failure to increase oogenesis in response to protein-rich diet. (2) A genetic approach will be used to determine whether increased fecundity of flies on high-protein diet is dependent on the function of period and timeless genes in the ovary, or in other organs such as the nervous system. (3) Expression of period and timeless will be investigated at the mRNA and protein level to determine whether it is affected by female age and nutritional status. (4) Biochemical tools will be used to elucidate the role of period and timeless in female fecundity. Accomplishment of these objectives will be aided by the wealth of genetic information and the ease of molecular manipulations in Drosophila, which make it an ideal system for the dissection of multi-component nutrient-fecundity pathway. The results of these studies will help to understand the functional significance of phylogenetically conserved clock genes in a genetic pathway regulating fecundity. Broader impact. Scientific program outlined here will facilitate partnerships between several faculty members, graduate, and undergraduate students. The proposed research will provide ample opportunities for training students; participants from groups underrepresented in science will be actively recruited to the program. The combination of physiological, molecular and genetic experiments will allow students to gain experience in the interdisciplinary approach to research. Students will be mentored with respect to their academic goals and encouraged to consider career in science. Dr. Giebultowicz has an excellent record of engaging undergraduate female students in her research and helping them to choose science as a career. The PI also integrate research activities into the teaching of science in area schools. She is a co-PI in the NSF-funded K-12 Rural Science Education Program at OSU, mentoring undergraduate and graduate students who help to teach science in selected rural schools in Oregon. She also participate in "Adventures in Learning" program for middle school girls, inviting students to the lab to conduct small experiment, offering hands-on approach to science. Research results obtained with NSF funds will be published in peer-reviewed journals, and research highlights will be posted on the laboratory web-site in a format accessible to the general public.