Understanding the Basis of Flight-enhanced Reproduction in Melanoplus sanguinipes

本研究将研究一种具有经济意义的迁徙蚱蜢（Melanoplus sanguinipes）的迁徙与繁殖之间的关系。先前的研究表明，这种昆虫的迁徙行为具有遗传基础，并且在整个昆虫的一生中，迁徙飞行的表现显著地加速了繁殖的开始并提高了繁殖力。这一观察结果挑战了迁移必然涉及生殖成本的传统假设。该提案涉及两个总体目标：确定飞行增强生殖所涉及的内分泌机制，以及长时间飞行对营养获取或利用的可能影响。为了实现第一个目标，将确定长时间飞行对神经激素的释放或合成的影响，这可能反过来导致与生殖有关的激素的模式和/或水平的变化。为了追求第二个目标，将确定飞行性能对交配和摄食这两个营养获取途径的影响。在模式物种中，雄性在交配时通过精子包囊转移为雌性提供营养。因此，本研究将确定长途飞行的表现是否会改变飞行后交配行为的频率或持续时间，如果确实如此，这种变化是否受到激素的调节。已有研究表明，在长时间飞行后，摄食活动不会增加，但本研究现在打算确定长时间飞行是否会提高食物利用率，以及这是否通过内分泌刺激发生。该项目的长期目标是通过遗传分析来分析这些生理关系的后果和局限性。本研究结果对研究昆虫生活史理论和进化的种群生物学家、研究昆虫内分泌关系的生理学家、研究昆虫生活史特征资源分配和协调的生理生态学家、以及研究控制血蛉和其他严重农业害虫的昆虫学家具有重要的参考价值。该项目将涉及少数民族和女性本科生（通常为4名学生/学期）。作为德克萨斯大学创新教师培训计划（UTeach）的一部分，该计划还将包括高中和初中数学和科学教师作为研究实习生（2名/学期）。

This study will examine the relationship between migration and reproduction in an economically significant migratory grasshopper, Melanoplus sanguinipes. Previous work has shown that migratory behavior has a genetic basis in this species and that the performance of migratory flight significantly accelerates onset of reproduction and enhances fecundity over the entire life of the insect. This observation challenges the conventional assumption that migration necessarily involves a reproductive cost. The proposal addresses two general objectives: to determine the endocrine mechanisms involved in flight-enhanced reproduction, and the possible effect of long-duration flight on nutrient acquisition or utilization. To accomplish the first objective, the effects of long-duration flight on the release or synthesis of neurohormones, that might in turn cause changes in the pattern and/or level of hormones involved in reproduction, will be determined. In pursuit of the second objective, the effect of flight performance on two avenues of nutrient acquisition, mating and feeding, will be determined. In the model species, males contribute nutrient to females at mating via spermatophore transfer with sperm. Thus, this study will establish whether the performance of long flight changes the frequency or duration of mating behavior after flight and if it does, whether this change is hormonally regulated. It has been shown that feeding activity does not increase after long flight, but this study now intends to establish whether performance of long-duration flight improves food utilization, and whether this occurs via endocrine stimulation.A long-term goal of this project is to analyze the consequences and limits of these physiological relationships through genetic analysis. The results of this work will be of interest to population biologists studying life history theory and evolution, physiologists interested in understanding endocrine relationships in insects, physiological ecologists interested in resource allocation and coordination of life history characters, and entomologists interested in controlling M. sanguinipes and other serious agricultural pests. This project will involve minority and women undergraduates (usually 4 students/semester). It will also involve pre-service math and science high school and middle school teachers as research interns (2/semester) as a part of an innovative new teacher-training program (UTeach) at The University of Texas.