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.

陆地环境中的两个主要周期是每天和季节性的。 动植物使用昼夜节律的内部时间来计时他们的日常活动。 许多植物，脊椎动物和昆虫都使用一天的长度（光周期）预测季节的变化，并适应其生长，发育，繁殖，开花，休眠或迁移的季节性活动。 这项研究涉及日常活动时间（昼夜节律）与季节性活动（光周期）之间的分子联系。 影响日常事件和季节性事件时机的最强烈的环境提示很轻。 虽然昼夜节律的光输入途径和分子基础是充分了解的，但对调节季节性周期的分子基础知之甚少。 这项研究使用投手植物蚊子Wyomyia Smithii专注于通过检查永恒基因的表达和作用来调节每日和季节周期的机制之间的联系，该基因已知，该基因对光的输入以及昼夜节律的中心功能在昆虫和虫子中的中心功能。 Wyeomyia Smithii生活在宽阔的纬度范围内，并且随着生长季节的长度在此范围内变化，用于在活跃的夏季发育和冬季休眠之间切换的一天长度也是如此。 对日长度的响应的差异将用于确定（1）永恒的表达模式如何随起源和日长的纬度而变化，以及（2）DNA水平的多态性与原点和日长的纬度不同。 这项研究的独特之处在于，它将不仅评估日常和季节性时序过程之间的联系，而且还表明，在分子水平上，连接通过进化时间在气候梯度上有何不同。