EDGE CT: Enabling cell-specific functional genomics in a colonial animal

摘要刺胞动物门是一组凝胶状的主要海洋动物，包括水母、珊瑚和海葵。大多数针胞体结构简单，具有径向对称。刺胞动物很重要的一个原因是，它们是所有两侧对称的动物的近亲，包括昆虫、蠕虫和脊椎动物。正因为如此，研究刺胞动物生物特征的分子或细胞基础，生物学家可以推断出这种特征在刺胞动物和两侧动物的祖先身上是如何起作用的。反过来，这可以帮助科学家了解这种特征目前在包括人类在内的更复杂的动物中是如何起作用的。在这个项目中，研究小组将开发工具来研究基因如何在一种叫做水螅的刺胞动物模式生物中起作用。水螅是一种理想的模式生物，因为它既便宜又容易饲养，而且不受伦理因素的限制。此外，Hydractinia是生物学家研究更复杂生物体的许多有趣过程的模型，包括再生，干细胞维持和移植组织的排斥。该项目的目标是允许生物学家在动物生命的任何空间位置和任何时间点研究任何细胞类型中的任何水螅基因。该项目开发的工具将与快速传播工作相配合，包括与更广泛的科学界共享协议和材料。此外，主要研究人员和他们的团队对教育和推广活动有着坚定的承诺，并计划了创造性的方法来吸引人们，包括K-12学生和公众。针孔动物是形态简单的动物，是双边动物的近亲。因此，它们是理解许多双边动物特征进化起源的关键。尽管在一些刺胞动物中有一些功能基因组学工具，但目前还不可能在细胞类型或时间/空间位置的水平上控制基因表达。对于过度表达或敲除/敲除对胚胎致命的基因的研究，以及研究特定环境的基因功能，这尤其成问题。此外，由于刺胞细胞特征的多样性，现有的刺胞细胞模式物种缺乏这些特征，就很难或不可能研究许多刺胞细胞特征，包括殖民地性、形态多态性、异体识别和干细胞多能性。本项目旨在建立共生水螅虫（Hydractinia symbiolongicarpus）细胞类型特异性功能基因组学。Aim 1的工作将侧重于使用单细胞RNAseq数据生成所有成年水螅细胞类型的基因表达图谱，随后鉴定和验证专属细胞类型标记，并为尽可能多的细胞类型生成转基因报告动物。Aim 2的工作将开发一个基于重组酶的条件基因敲除系统，包括允许细胞类型特异性重组酶的菌株和Hydractinia条件等位基因的菌株。已经计划了一系列不同的活动，以便向更广泛的科学界迅速传播这个项目产生的工具和技术。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。

Public Award AbstractThe phylum Cnidaria is a group of gelatinous, primarily marine animals that includes jellyfish, corals, and sea anemones. Most cnidarians are structurally simple and have radial symmetry. One reason that cnidarians are important is that they are the closest relatives of all bilaterally symmetrical animals, a group that includes insects, worms, and vertebrates. Because of this, studying the molecular or cellular basis of a biological trait in a cnidarian allows biologists to infer how that trait might have functioned in the ancestors of cnidarians and bilaterians. This, in turn, can help scientists understand how the trait currently functions in more complex animals, including humans. In this project, the research team will develop tools to study how genes function in a cnidarian model organism called Hydractinia. Hydractinia is an ideal model organism because it is inexpensive and easy to maintain, and not restricted by ethical considerations. In addition, Hydractinia is a model for many processes that are interesting to biologists studying more complex organisms, including regeneration, stem cell maintenance, and the rejection of transplanted tissues. The goal of this project is to allow biologists to study any Hydractinia gene in any cell type at any spatial location and at any timepoint during the animal's life. The tools developed in this project will be paired with rapid dissemination efforts, including the sharing of protocols and materials with the broader scientific community. In addition, the principal investigators and their teams share a strong commitment to education and outreach activities, and have planned creative methods to engage people, including K-12 students and the general public.Technical AbstractCnidarians are morphologically simple animals and the closest relatives of bilaterians. As such, they are key to understanding the evolutionary origin of many bilaterian features. Despite the availability of some functional genomics tools in a few cnidarians, it is not currently possible to control gene expression at the level of cell type or temporal/spatial location. This is particularly problematic for the study of genes for which overexpression or knockdown/knockout is embryonic lethal, and for studying context-specific gene function. Moreover, due to the diversity of cnidarian characters, it is either difficult or impossible to study many cnidarian traits, including coloniality, morphological polymorphism, allorecognition, and stem cell pluripotency in existing cnidarian model species that lack these features. This project aims to develop cell type-specific functional genomics in the hydrozoan Hydractinia symbiolongicarpus. Work in Aim 1 will focus on generating an atlas of gene expression for all adult Hydractinia cell types, using single-cell RNAseq data, followed by identifying and validating exclusive cell type markers and generating transgenic reporter animals for as many cell types as possible. Work in Aim 2 will develop a recombinase-based conditional gene knockout system including strains that permit cell type-specific recombinases and strains for conditional alleles in Hydractinia. A diverse set of activities have been planned to rapidly disseminate the tools and techniques resulting from this project to the broader scientific community.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.