Roles of clock genes in modulation of Drosophila oogenesis

A.项目概要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理想模型，但目前对果蝇生物钟基因的功能意义知之甚少。由Giebultowicz博士领导的研究小组证明了外周生物钟在生殖生理学中起着多种作用。最近的研究表明，两个重要的时钟基因，周期和时间，参与调节女性生殖力。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。一个综合的生理和分子的方法，提出了调查这种新的健身相关的表型。初步数据导致了一个假设，即由周期和时间编码的蛋白质是调节产蛋速率的信号通路的一部分。 这一假设将在一个分为四个目标的实验计划中进行测试。 (1)将在突变型和野生型雌性之间比较生殖生理学的几个方面，以确定突变型雌性是否具有改变的内分泌功能或其他生理参数，这些生理参数可能解释它们未能响应于富含蛋白质的饮食而增加卵子发生。(2)遗传学方法将用于确定高蛋白饮食的果蝇繁殖力增加是否取决于卵巢或其他器官（如神经系统）中周期和永恒基因的功能。(3)将在mRNA和蛋白质水平上研究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)生物化学工具将被用来阐明女性生殖力的作用时期和永恒。果蝇丰富的遗传信息和易于进行的分子操作将有助于这些目标的实现，这使其成为解剖多组分营养-生殖途径的理想系统。这些研究结果将有助于了解在生殖力调控的遗传途径中，在遗传学上保守的时钟基因的功能意义。更广泛的影响。这里概述的科学计划将促进几个教师，研究生和本科生之间的伙伴关系。拟议的研究将为培训学生提供充足的机会;来自科学代表性不足的群体的参与者将被积极招募到该计划中。生理，分子和遗传实验的结合将使学生获得跨学科研究方法的经验。学生将得到指导，尊重他们的学术目标，并鼓励考虑在科学事业。 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还将研究活动纳入地区学校的科学教学中。她是一个共同PI在NSF资助的K-12农村科学教育计划在俄勒冈州立大学，指导本科生和研究生谁帮助在俄勒冈州选定的农村学校教科学。她还参加了“学习的冒险”计划，为中学女生，邀请学生到实验室进行小实验，提供动手的方法来科学。用NSF基金获得的研究结果将发表在同行评审的期刊上，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.