Mechanisms and Evolutionary Consequences of a Reproduction-Immunity Tradeoff

项目总结 所有有机体都必须同时平衡多种相互竞争的需求，以满足它们的能量和 生理资源。这可能会导致性状之间的冲突，推动生理和进化 权衡取舍。对感染的防御和繁殖能力都是在强烈的自然选择下进行的 作为进化适应性的重要贡献者，两者都是能量要求很高的，也都是权衡的 两者之间几乎普遍存在于动植物中，包括那些具有公共健康的动植物。 重要性。然而，尽管它们无处不在，也很重要，但令人惊讶的是，人们对这一机制知之甚少 生殖免疫权衡的基础。知识中的这一缺陷限制了对 进化过程，并对控制昆虫的干预措施的能力施加实际限制 农业或公共卫生领域的有害生物。拟议的项目将使用易驯服的昆虫模型 黑腹果蝇研究生殖投资制约机制 免疫性能，探索这种权衡的进化含义，并提供罕见的 了解生活史权衡是如何产生和维持的。该项目将测试 荷尔蒙的多效性理论，该理论假设内分泌信号可以作为一种主要的调节作用 塑造生活史的权衡，重点是昆虫保幼激素(JH)。初步实验将 确定JH信号对交配反应的时间动力学及其定量关系 JH信号强度与免疫抑制程度之间的关系。随后的实验将 确定JH抑制免疫的机制，寻求确定新的调节机制 过程，测试一个假设，即权衡可能通过对蜂窝基础设施的压力而产生，以及 确定免疫抑制是否可以与生殖投资脱钩。其他内容 实验将测试JH信号中自然发生的遗传变异是否决定了自然 生殖-免疫权衡大小的表型变异性以及是否精力充沛 生殖产出所需的投资直接限制了免疫防御的质量。数据 所获得的将包括对焦点系统的深入研究，并将揭示可以 在不同的系统中泛化。

PROJECT SUMMARY All organisms must simultaneously balance multiple competing demands on their energetic and physiological resources. This can result in conflict among traits, driving physiological and evolutionary tradeoffs. Defense against infection and reproductive capacity are each under strong natural selection as important contributors to evolutionary fitness, both are energetically demanding, and tradeoffs between the two are nearly universal in plants and animals, including those with public health importance. Yet despite their ubiquity and importance, surprisingly little is known about the mechanistic basis for reproduction-immunity tradeoffs. This shortcoming in knowledge limits inference about the evolutionary process and applies practical limitations on the capacity for interventions to control insect pests in agricultural or public health contexts. The proposed project will use the tractable model insect Drosophila melanogaster to determine mechanisms by which reproductive investment constrains immune performance, exploring the evolutionary implications of the tradeoff and providing rare understanding of how life history tradeoffs arise and are maintained. The project will test of the hormonal theory of pleiotropy, which posits that endocrine signaling can act as a master regulator to shape life history tradeoffs, with a focus on insect Juvenile Hormone (JH). Initial experiments will determine the temporal kinetics of JH signaling in response to mating and the quantitative relationship between JH signal intensity and degree of immune suppression. Subsequent experiments will determine the mechanisms by which JH suppresses immunity, seeking to identify novel regulatory processes, testing a hypothesis that the tradeoff can arise through strain on cellular infrastructure, and determining whether immunosuppression can be decoupled from reproductive investment. Additional experiments will test whether naturally occurring genetic variation in JH signaling determines natural phenotypic variability in the magnitude of the reproduction-immunity tradeoff and whether energetic investment required for reproductive output directly limits the quality of immune defense. The data obtained will comprise an in-depth study of the focal system and will reveal principles that can be generalized across diverse systems.