Evolution of Photoperiodic Time Measurement and the Circadian Clock in Animals: Perspectives from the Pitcher-Plant Mosquito, Wyeomyia smithii

动物光周期时间测量和昼夜节律的演变：来自猪笼草蚊子 Wyeomyia smithii 的视角

• 批准号: 0445710
• 负责人: William Bradshaw
• 金额: --
• 依托单位: University of Oregon Eugene
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-08-15 至 2010-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0445710&HistoricalAwards=false
• 关键词: Evolution; Photoperiodic; Time; Measurement; Circadian

Evolution of Photoperiodic Time Measurement and the Circadian Clock in Animals: Perspectives from the Pitcher-Plant Mosquito, Wyeomyia smithiiWilliam E. BradshawUniversity of Oregon EugeneEvolution of life cycles that are compatible with the changing seasons is a major feature of temperate organisms. No life cycle in a temperate zone like North America can be complete without the ability to exploit the favorable season, the ability to mitigate or avoid the unfavorable season, and the ability to switch from one lifestyle to the other on a timely basis. The most prominent switching mechanism used by temperate plants and animals to anticipate and prepare for the changing seasons is the length of day or photoperiod. Evolution of photoperiodic response is a major feature of the geographic dispersal of invading species and, as prior funding to this lab by NSF has recently shown, adaptation to rapid climate change. This research examines the physiological and genetic processes within and between populations that ultimately constitute the basis for the diversity of seasonal adaptations observed over a continental scale at temperate latitudes. The main objective of this work is to test whether there is a necessary, causal connection between the "daily" (circadian) clock controlling daily activities and the "seasonal" (photoperiodic) timer controlling seasonal activities. Daily activities include sleep-wakefulness patterns and hunger cycles in humans; disruption of the circadian clock is responsible for "jet lag." Seasonal cycles include migration in birds, hibernation in mammals, and dormancy and reproduction in a wide array of animals under natural conditions. The genetic basis of daily clocks is fairly well understood, but little is known about the genetic basis of the seasonal timer, let alone how the two processes relate to each other. The work in this proposal will test for the genetic flexibility of the connection between the daily and the seasonal timer by employing a set of artificial selection experiments. Knowledge of the potential interaction between these two timing mechanisms is fundamental to understanding how temperate organisms expand their ranges, time events as diverse as dormancy and reproduction, and cope with climate change. North America is undergoing a period of unprecedented climate change that is imposing strong natural selection for altering the timing of seasonal activities. The experiments to be run will show whether and how modification of the seasonal timer affects the daily clock and vice versa. Understanding the genetics underlying seasonal adaptation will assist in evaluating the survival of important agricultural crops, the spread of vector-borne diseases, the impact of agricultural pests, and the composition of natural biotic communities. This research lends itself well to undergraduate participation, not just as research assistants, but also as young investigators pursuing related but independent projects. Recent undergraduate students from this lab have continued on to graduate or medical school, to careers as teachers, applied biologists, lawyers, journalists, and to other professions not related to science. Regardless of their future endeavors, these students constitute an informed citizenry, more aware of basic research, its importance, and its implications. This research will continue a strong tradition and commitment to undergraduate research participation and training by this laboratory.

动物光周期时间测量和昼夜节律的演变：从猪笼草蚊子 Wyeomyia smithii 的角度来看威廉·E·布拉德肖俄勒冈大学尤金分校生命周期的演变与季节变化相适应是温带生物的一个主要特征。 如果没有利用有利季节的能力、减轻或避免不利季节的能力以及及时从一种生活方式转向另一种生活方式的能力，像北美这样的温带地区的生命周期就不可能完整。 温带植物和动物用来预测和准备季节变化的最重要的转换机制是白天的长度或光周期。 光周期反应的进化是入侵物种地理扩散的一个主要特征，正如美国国家科学基金会最近对该实验室的资助所表明的那样，光周期反应的进化是对快速气候变化的适应。 这项研究研究了种群内部和种群之间的生理和遗传过程，这些过程最终构成了在温带纬度大陆范围内观察到的季节性适应多样性的基础。 这项工作的主要目的是测试控制日常活动的“日常”（昼夜节律）时钟和控制季节性活动的“季节性”（光周期）计时器之间是否存在必要的因果关系。 日常活动包括人类的睡眠-觉醒模式和饥饿周期；生物钟的破坏是造成“时差反应”的原因。 季节性周期包括鸟类的迁徙、哺乳动物的冬眠以及自然条件下多种动物的休眠和繁殖。 日常时钟的遗传基础已被很好地理解，但人们对季节性计时器的遗传基础知之甚少，更不用说这两个过程如何相互关联了。 该提案中的工作将通过采用一组人工选择实验来测试每日计时器和季节性计时器之间连接的遗传灵活性。 了解这两种计时机制之间的潜在相互作用对于理解温带生物如何扩大其范围、休眠和繁殖等多样化的时间事件以及应对气候变化至关重要。 北美正在经历前所未有的气候变化时期，强烈的自然选择改变了季节性活动的时间。 即将进行的实验将显示季节性计时器的修改是否以及如何影响每日时钟，反之亦然。 了解季节性适应的遗传学将有助于评估重要农作物的生存、媒介传播疾病的传播、农业害虫的影响以及自然生物群落的组成。 这项研究非常适合本科生参与，不仅作为研究助理，而且还作为追求相关但独立项目的年轻研究人员。 该实验室最近的本科生继续攻读研究生或医学院，从事教师、应用生物学家、律师、记者以及其他与科学无关的职业。 无论他们未来的努力如何，这些学生都是知识渊博的公民，更加了解基础研究及其重要性和影响。 这项研究将延续该实验室对本科生研究参与和培训的强大传统和承诺。