Dissertation Research: Circadian-Clock Genes and Variation in Photoperiodic Time Measurement: a Role for Timeless?

论文研究：昼夜节律时钟基因和光周期时间测量的变异：Timeless 的作用？

• 批准号: 0408154
• 负责人: William Bradshaw
• 金额: $ 1.2万
• 依托单位: University of Oregon Eugene
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-06-01 至 2005-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0408154&HistoricalAwards=false
• 关键词: Dissertation; Research; Circadian; Clock; Genes

The two major cycles in terrestrial environments are daily and seasonal. Plants and animals use an internal circadian clock to time their daily activities. Many plants, vertebrates, and insects use the length of day (photoperiod) to anticipate the changing seasons and to time their seasonal activities of growth, development, reproduction, flowering, hibernation, or migration accordingly. This research is concerned with the molecular connection between the timing of daily activities (circadian rhythmicity) and seasonal activities (photoperiodism). The strongest environmental cue affecting the timing of both daily and seasonal events is light. Whereas the light-input pathway and molecular basis of circadian rhythmicity are well understood, little is known about the molecular basis of the regulation of seasonal cycles. This research uses the pitcher-plant mosquito, Wyeomyia smithii, to focus on the connection between the mechanisms regulating daily and seasonal cycles by examining the expression and role of the timeless gene, a gene known to be essential for the input of light and the central functioning of the circadian clock in insects and vertebrates. Wyeomyia smithii lives over a broad latitudinal range and, as the length of the growing season changes over this range, so also does the day length used to switch between active summer development and winter dormancy. This divergence of response to day length will be used to determine (1) how the expression patterns of timeless vary with latitude of origin and day length and (2) how polymorphism at the level of DNA varies with latitude of origin and day length. This research is unique in that it will be evaluating not only the connection between the daily and seasonal timing processes, but also show how at the molecular level that connection varies over a gradient of climate through evolutionary time.

陆地环境的两个主要周期是每日和季节性。 植物和动物使用内部生物钟来计时其日常活动。 许多植物、脊椎动物和昆虫利用一天的长度（光周期）来预测季节的变化，并相应地安排其生长、发育、繁殖、开花、冬眠或迁徙的季节性活动。 这项研究涉及日常活动时间（昼夜节律）和季节性活动（光周期）之间的分子联系。 影响日常和季节性事件时间的最强环境线索是光。 尽管昼夜节律的光输入途径和分子基础已广为人知，但对季节周期调节的分子基础却知之甚少。 这项研究使用猪笼草蚊子 Wyeomyia smithii，通过检查永恒基因的表达和作用，重点关注调节日常和季节周期的机制之间的联系，该基因已知对光输入和中枢神经系统至关重要。昆虫和脊椎动物的生物钟的功能。 Wyeomyia smithii 生活在广泛的纬度范围内，随着生长季节长度在该范围内变化，用于在夏季活跃发育和冬季休眠之间切换的日长也会发生变化。 这种对日长反应的差异将用于确定 (1) timeless 的表达模式如何随起源纬度和日长变化，以及 (2) DNA 水平的多态性如何随起源纬度和日长变化。 这项研究的独特之处在于，它将不仅评估日常和季节计时过程之间的联系，而且还将在分子水平上展示这种联系如何随着进化时间的气候梯度而变化。