BRC-BIO: Effects of insecticides on survival and metamorphosis of the upside-down jellyfish, Cassiopea xamachana, and its symbiotic community

珊瑚礁具有巨大的生态重要性，还通过海岸保护、旅游以及作为食物和药品的来源提供经济和社会价值。此外，它们是复杂的生物体，在它们的细胞上和细胞内生活着不同的细菌群落(由全菌、有机体及其共生体组成)。然而，对这些全息图的研究有很大的局限性。在这个项目中，密切相关的倒置水母(仙后座水母)被开发为了解环境对近岸珊瑚影响的模型。这些水母含有相似但不那么复杂的细菌群落，数量丰富，收集起来不复杂，很容易在实验室条件下进行研究。利用杀虫剂暴露(与蚊子控制有关)作为近岸常见的应激源，该项目将量化暴露对全食水母所有成员的生存和生长变化的影响，以及水母细菌微生物群的功能和相互作用的变化。除了有可能更多地了解影响佛罗里达群岛珊瑚群落的过程外，该项目还将允许更多的本科生接触科学研究和生物学领域，让他们有机会考虑以研究为基础的职业。通过在一所拥有高比例第一代学生和有色人种学生的机构中扩大本科生研究，可以拓宽参与生物学研究的声音，同时也为科学界带来新的思维和处理问题的方法。该项目的总体主题是推进C.xamachana光共生全瘤菌作为一个实验系统，研究线虫相关的个体微生物、光共生菌和息肉全瘤菌，以及杀虫剂暴露对这些系统的影响。由于其复杂的生活史，多种多样的刺齿目动物提供了许多潜在的目标，也允许杀虫剂以不同的方式到达沿海水域。然而，很少有人研究杀虫剂暴露对珊瑚存活的影响，也没有研究对光共生共生科或细菌/古生菌微生物组的影响，这些微生物对线虫健康是不可或缺的。Xamachana是开始区分每个微生物成员在光共生线虫生命周期对杀虫剂暴露的反应中所起作用的理想系统。Xamachana表现出一个无性息肉生活期，只有在光共生建立后才终止，这一事件伴随着从无柄息肉到幼体水母的明显发育转变。在发育过渡期间，细菌基因表达对杀虫剂暴露的响应变化将使用下一代测序进行询问。高分辨率显微镜和荧光原位杂交将定位水母中感兴趣的细菌。通过将这些方法与对共生科和细菌培养个体的息肉、神经网络功能和生长的检查相结合，我们可以了解在佛罗里达群岛接触三种用于控制蚊子的杀虫剂如何影响不同的刺齿动物全叶虫。这些结果可以为佛罗里达珊瑚礁地区的保护决策提供参考，该地区受到严重疾病爆发的威胁，可能会对压力较大的珊瑚产生更强烈的影响，例如那些暴露在杀虫剂中的珊瑚。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。

Coral reefs are of tremendous ecological importance and also provide economic and social value through coastal protection, tourism, and as a source of food and pharmaceuticals. Further, they are complex organisms that have a diverse bacterial community living on and in their cells (comprising a holobiont, the organism and its symbionts). However, there are significant limitations to the study of these holobionts. In this project, the closely-related upside-down jellyfish (Cassiopea xamachana) is developed as a model for understanding environmental effects on nearshore corals. These jellyfish contain a similar but less complex bacterial community, are abundant, uncomplicated to collect, and easy to study under laboratory conditions. Using insecticide exposure (associated with mosquito control) as a common near shore stressor, the project will quantify the effects of exposure on survival and changes in growth of all members of the holobiont, as well as changes in the function and interactions of the jellyfish bacterial microbiome. In addition to the potential to learn more about processes that will affect the coral community in the Florida Keys, this project will allow more undergraduate students to access scientific research and the field of biology, giving them an opportunity to consider research-based careers. By expanding undergraduate research at an institution with a high proportion of first-generation students and students of color, the voices involved in biology research can be broadened, while also bringing new ways of thinking and approaching problems to the scientific community.The overarching theme of this project is to advance the C. xamachana photosymbiotic holobiont as an experimental system for studies on cnidarian associated individual microbes, the photosymbiont, and the polyp holobiont as well as the impact of insecticide exposure on these systems. The diverse cnidarian holobiont with its complex life cycle offers many potential targets also allows for the diverse ways insecticides that reach coastal waters. However, little work has been done to investigate the effects of insecticide exposure on coral survival, nor on the photosymbiotic Symbiodiniaceae or bacterial/archaeal microbiome which are integral to cnidarian health. C. xamachana is the ideal system to begin to discriminate the roles each microbial member plays in the response of a photosymbiotic cnidarian life cycle to insecticide exposure. C. xamachana exhibits an asexual polyp life stage that is only terminated after the establishment of photosymbiosis, an event accompanied by a distinct developmental transition from sessile polyp to juvenile medusa. Changes in bacterial gene expression in response to insecticide exposure during that developmental transition will be interrogated using next-generation sequencing. High-resolution microscopy and fluorescence in situ hybridization will localize bacteria of interest in the jellyfish. By combining these approaches with an examination of polyp nerve net function and growth of individual Symbiodiniaceae and bacterial cultures we can understand how exposure to the three insecticides used for mosquito control in the Florida Keys affects the diverse cnidarian holobiont. These results can inform conservation decisions on the Florida reef tract, threatened by a severe disease outbreak that may more strongly impact stressed corals, such as those exposed to insecticides.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.