DISSERTATION RESEARCH: Molecular characterization of photoperiod effects on social ontogeny in a bumble bee

光周期被定义为阳光的周期性变化，是个体能够感知到的预测环境变化的最可靠的外部信号之一。大黄蜂的生活周期(例如，蜂群的生长和发展；行为)与光照的季节性变化保持着紧密的联系。该项目的主要假设是，光周期是大黄蜂群体在其生命周期中通过连续步骤转移的一种信号。这一假设将从三个不同的角度进行评估，使用北美本土大黄蜂Bombus impatiens。首先，这项研究将通过操纵光/暗循环来确定光周期对菌落发育的影响。其次，光周期对个体行为的影响将通过视频记录分析来量化。第三，这项研究将利用大黄蜂大脑中的基因表达和时钟蛋白定位来表征生物钟分子组成的差异。预计随着日长的增加，处理将产生更大的蜂群，并同步产生新的雄蜂和蜂王。在分子水平上，预测光周期的变化将与时钟基因表达谱的变化相关，并将影响时钟蛋白在大脑中的定位。这个项目将结合行为研究和分子分析，对光周期对凤仙花的社会组织和生活史的影响进行基本但完整的概述。大黄蜂是农作物和其他植物的重要传粉者。近几十年来，全球范围内大黄蜂和传粉者的数量普遍减少。很少有研究讨论光周期如何影响传粉者，以及它们由于气候变化而进入新环境的情况。调查员积极参与外联活动，该项目将包括一名研究生的培训、本科生的指导和公开研讨会。

Photoperiod, defined as the cyclical change of sunlight, is one of the most reliable external signals that individuals can perceive to predict environmental changes. Bumble bees maintain a tight association of their life cycle (e.g., colony growth and development; behavior) with seasonal changes in light. The main hypothesis of this project is that photoperiod is a cue that a bumble bee colony uses to shift through consecutive steps during its life cycle. This hypothesis will be evaluated from three different perspectives using the North American native bumble bee Bombus impatiens. First, this study will determine the effects of photoperiod on colony development through manipulations of the Light/Dark cycle. Second, the effect of photoperiod on individual behavior will be quantified using video recording analysis. Third, the study will characterize differences in the molecular components of the circadian clock using gene expression and clock protein localization in the bumble bee brain. It is expected that treatments with increasing day length will produce larger colonies and a synchronized production of new males and queens. At the molecular level is it predicted that changes in photoperiod will correlate with changes in clock gene expression profiles and will affect the localization of clock proteins in the brain. This project will integrate behavioral research and molecular analysis to yield a basic but complete overview of the effects of photoperiod on the social organization and life cycle of B. impatiens. Bumblebees are important pollinators of crops and other plants. In recent decades there has been a worldwide reduction in the populations of bumble bees, and of pollinators in general. Few studies have addressed how photoperiod can affect pollinators and their movements into new environments due to climate change. The investigator is actively involved in outreach activities and this project will involve training of a graduate student, mentorship of undergraduates and public seminars.