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

催乳素通常被称为“父母的荷尔蒙”，因为在许多动物中，这种荷尔蒙在维持父母的行为方面具有明确和公认的作用。然而，鸟类专性幼体寄生虫有一个季节性的催乳素高峰，这些寄生虫将蛋留在不同物种的巢中，而不是自己筑巢、孵化自己的蛋和喂养自己的新生儿。在对后代没有帮助的物种中，催乳素水平升高表明，在评估这种激素的水平如何激励父母照顾时，循环中的催乳素水平可能是不足的或具有误导性的。这项研究将考察鸟类幼虫中催乳素和父母照顾之间的脱节。这些研究的目的是确定父母行为的分子和神经生理学基石，以及这些基石的改变如何导致父母关怀的显著变化。此外，这些研究还利用现代基因操作方法研究了改变催乳素受体对父母行为的影响，这些方法增加了巢寄生虫大脑中催乳素受体的丰度，降低了非寄生鸟的催乳素受体丰度。公民科学家将参与这些研究的领域部分，包括来自促进女孩与女科学家互动的项目的学生，以便他们可能将科学职业视为现实的选择。这项研究中使用的机器鸟也将成为夏令营的一个组成部分，该夏令营将向高中生介绍使用机器人进行的生物实验。尖端的基因操作方法将为本科生在实验室课程中提供实践经验。在许多物种中，父母的照顾对后代的生存至关重要。然而，不同物种、不同性别和不同个体的父母照顾方式存在着深刻的差异。这些比较研究利用父母照料的自然差异来确定鸟类幼鸟寄生行为的神经生物学和分子基础。鸟类专性幼虫通过在其他物种的巢中产卵来逃避向后代提供父母照顾，这使寄生虫从父母的任务中解脱出来，但确保寄生的后代得到必要的供应，直到它们独立。然而，一些幼虫寄生物种表现出催乳素的季节性激增，催乳素是一种被公认为“亲代激素”的荷尔蒙。这些研究包括实地研究和实验室研究相结合，旨在了解幼虫寄生物种中催乳素和父母照顾之间的脱节。这些目的是跟踪两个亲缘关系密切、父母照料方式截然不同的物种的催乳素依赖生理和行为发育，并确定催乳素生理是否在亲缘关系遥远的亲缘关系较远的寄生物种中表现出趋同的特征。需要研究的催乳素相关生理学包括循环催乳素、催乳素受体亚型和催乳素调节的细胞内信使系统，特别是Janus激酶/信号转导和转录激活因子(即JAK/STAT途径)。将使用腺相关病毒和RNAi方法，在发育和繁殖状态以及具有改变催乳素受体的转基因寄生鸟和非寄生鸟中，研究对机器人雏鸟的催乳素依赖的行为反应。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械论观点，并为与新的行为表型相关的可能的神经生物学机制提供洞察。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.