RUI: Examining the disconnect between prolactin and parental care in avian brood parasites

催乳素通常被称为“亲代激素”，因为在许多动物中，这种激素在维持亲代行为方面发挥着明确而成熟的作用。然而，鸟类专育寄生物的催乳素有一个季节性高峰，这是一种将蛋留在不同物种的巢中而不是自己筑巢，孵化自己的蛋并喂养自己的新生儿的鸟类。在对后代没有帮助的物种中，催乳素升高表明循环催乳素水平可能不足或误导评估这种激素水平如何激发亲代照顾。这些研究将检查在禽类寄生虫中催乳素和亲代护理之间的脱节。这些研究的目的是确定亲代行为的分子和神经生理组成部分，以及这些组成部分的修改如何导致亲代护理的惊人转变。此外，这些研究利用现代基因操作方法研究了改变催乳素受体对亲代行为的影响，这些方法增加了巢寄生虫大脑中催乳素受体的丰度，降低了非寄生鸟类的催乳素受体丰度。公民科学家将参与这些研究的实地部分，包括来自促进女孩与女科学家互动的项目的学生，以便她们将科学职业视为现实的选择。研究中使用的机器鸟也将成为暑期研究营的一部分，向高中生介绍使用机器人技术进行生物实验。尖端的基因操作方法将为本科生在实验课程中提供实践经验。在许多物种中，亲代抚育对后代的生存至关重要。然而，在不同物种、性别和个体之间，亲代养育存在着深刻的差异。这些比较研究利用亲代抚育的自然变化来确定鸟类幼虫寄生行为的神经生物学和分子基础。鸟类专性寄主通过在其他物种的巢中产卵来逃避对后代的亲代照顾，这使寄主从亲代的任务中解脱出来，但确保寄主后代获得必要的供给，直到它们独立。然而，一些幼虫寄生物种显示出催乳素的季节性激增，催乳素是一种公认的“亲代激素”。这些研究包括实地和实验室研究的混合，旨在了解在育成寄生物种中催乳素和亲代护理之间的脱节。这些研究旨在追踪两种亲代抚育方式截然不同的亲代亲缘关系密切的寄生物种的催乳素依赖性生理和行为，并确定催乳素生理是否在亲代亲缘关系较远的寄生物种中表现出趋同特征。要研究的催乳素相关生理学包括循环催乳素、催乳素受体异构体和催乳素调节的细胞内信使系统，特别是janus激酶/信号转导器和转录激活因子（即JAK/STAT途径）。利用腺相关病毒和RNAi方法，研究了催乳素依赖性行为对机器人雏鸟的发育和繁殖状况，以及催乳素受体改变的转基因寄生和非寄生鸟类的反应。这些研究将为理解幼虫寄生的进化提供一个期待已久的机制视角，并为与新行为表型相关的可能的神经生物学机制提供见解。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Prolactin is often referred to as the “parental hormone” because there is a clear and well-established role for this hormone in maintaining parental behavior in many animals. Yet, there is a seasonal prolactin peak in avian obligate brood parasites, which are birds that leave their eggs in nests of different species rather than build their own nest, incubate their own eggs and feed their own newborns. Elevated prolactin in species that provide no help to their offspring indicates that circulating prolactin levels may be insufficient or misleading in assessing how levels of this hormone motivate parental care. The studies will examine the disconnect between prolactin and parental care in avian brood parasites. The aim of these studies is to identify the molecular and neurophysiological building blocks of parental behavior and how modification in these building blocks result in striking transformations in parental care. Additionally, these studies investigate consequences of altering prolactin receptor on parental behaviors using modern gene manipulation approaches that increase prolactin receptor abundance in the brain of nest parasites and decrease prolactin receptor abundance in non-parasitic birds. Citizen scientists will participate in the field components of these studies, including students from programs promoting interaction of girls with female scientists so that they may view science careers as realistic options. Robotic birds used in the research will also be a component of summer research camps that will introduce high school students to biological experiments using robotics. Cutting-edge gene manipulation approaches will provide hands-on experience for undergraduate students in lab courses.Parental care is critical for survival of offspring in many species. Yet, there are profound differences in parental care across species, sexes and individuals. These comparative studies take advantage of natural variation in parental care to identify the neurobiological- and molecular-basis of brood parasitic behavior in birds. Avian obligate brood parasites evade providing parental care to offspring by laying eggs in nests of other species, which releases the parasite from parental tasks but ensures that parasitic offspring receive necessary provisioning until they are independent. Some brood parasitic species, however, display seasonal surges in prolactin, a hormone well-established as the “parental hormone”. These studies include a blend of field and laboratory studies aimed at understanding the disconnect between prolactin and parental care in brood parasitic species. These aims track prolactin-dependent physiology and behavior across development in two closely related species with stark differences in parental care and identify whether prolactin physiology exhibits convergent features across phylogenetically distantly related brood parasitic species. The prolactin-related physiology to be investigated includes circulating prolactin, prolactin receptor isoforms and prolactin-regulated intracellular messenger systems, specifically the janus kinase/signal transducers and activators of transcription (i.e. JAK/STAT pathway). Prolactin-dependent behavioral responses to robotic nestlings will be investigated across development and breeding status as well as in transgenic parasitic and non-parasitic birds with altered prolactin receptors using adeno-associated virus and RNAi approaches. These studies will provide a long overdue mechanistic perspective to understanding the evolution of brood parasitism and provide insight into possible neurobiological mechanisms associated with novel behavioral phenotypes.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.