Collaborative Research: Adaptation or opportunity? Using mammal sucking lice to determine drivers of host-parasite associations

寄生是地球上最常见的生命形式之一。然而，为什么生物体寄生于某些物种而不寄生于其他物种，这在很大程度上是未知的。吸吮虱寄生于一种或几种哺乳动物宿主物种，但目前尚不清楚这种有限数量的宿主是由于虱子无法寄生于其他物种还是仅仅缺乏遇到其他宿主的机会。该研究项目将调查包括人类虱子在内的吸虱的进化史、基因和物理特征如何决定它们可以寄生的宿主物种。这些发现还将确定潜在的重要遗传和生理特征，以便在其他寄生虫中进行研究。更广泛地说，这项研究可以用来帮助了解寄生虫转移到新宿主的可能性，并有助于减少或减轻新寄生虫的后果。该项目将培养学生和研究人员的尖端研究方法，生成大学水平的课程，并使用虚拟现实体验来教育公众关于虱子的多样性及其特征。为了研究吸吮虱的选择和适应性，本项目将利用高通量测序技术建立哺乳动物吸吮虱（Anoplura）的第一个系统基因组树。接下来，该项目将通过新颖的机器学习算法生成虱子形态特征和空间分布数据库，以挖掘物种描述。第三，本研究将整合虱的编码基因和基因组，并利用纳米oct扫描和几何形态计量学来表征寄生于同一寄主物种的远亲虱类群的表型特征。这些数据集将被整合到：1)确定虱子多样化事件和测试宿主-寄生虫共多样化，2)检查虱子形态特征的进化以及虱子性状与宿主性状的关联，3)评估虱子的生物地理历史和相对于宿主的分布，以及4)确定哪些基因组和形态特征在选择中促进了寄生。这个项目将确定虱子的多样化和寄主关联是否主要是由历史和寄主适应驱动的，或者虱子的适应是否允许寄主的多样性，但由于传播有限而仅限于一个或几个寄主物种，并最终解决“为什么以及如何成为寄生虫”这个问题？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。

Parasitism is one of the most common forms of life on the planet. However, it is largely unknown why organisms parasitize some species but not others. Sucking lice parasitize one or a few mammal host species, but it is unclear if this limited number of hosts is due to the inability of a louse to parasitize other species or simply lack of opportunity to encounter additional hosts. This research project will investigate how the evolutionary history, genes, and physical traits of sucking lice, including human lice, determine what host species they can parasitize. These findings will also identify potential genetic and physical traits important in parasitism to investigate in other parasites. More broadly, this research can be used to help understand the likelihood of a parasite moving to a new host and help to reduce or mitigate the consequences of new parasites. This project will train students and researchers in cutting-edge research methods, generate college-level curricula, and use virtual reality experiences to educate the public about the diversity of lice and their traits. To investigate selection and adaptations in sucking lice, this project will use high-throughput sequencing to build the first phylogenomic tree for mammalian sucking lice (Anoplura). Next, the project will generate a database of louse morphological characters and spatial distributions through novel machine learning algorithms to mine species descriptions. Third, this investigation will assemble louse coding genes and genomes and use nanoCT scanning and geometric morphometrics to characterize phenotypic traits of distantly related louse taxa parasitizing the same host species. These datasets will be integrated to: 1) date louse diversification events and test for host-parasite codiversification, 2) examine the evolution of louse morphological characters and association of louse traits with host characters, 3) assess louse biogeographic histories and distributions relative to hosts, and 4) determine which genomic and morphological traits are under selection to facilitate parasitism. This project will determine if louse diversification and host associations are primarily driven by history and host adaptations, or if louse adaptations could permit parasitism of a diversity of hosts but are restricted to one or a few host species due to limited dispersal and ultimately address the question, “Why and how to be a parasite?”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.