Collaborative Research: How do predators spread disease? Tests of five ecological and eco-evolutionary mechanisms with disease in the plankton

合作研究：捕食者如何传播疾病？

• 批准号: 1655665
• 负责人: Carla Caceres
• 金额: $ 40万
• 依托单位: University of Illinois at Urbana-Champaign
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-07-15 至 2022-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1655665&HistoricalAwards=false
• 关键词: Collaborative; Research; How; do; predators

A practical goal of disease ecologists is to find ways to stop or slow the spread of infection from host to host. A popular idea is that predators control disease outbreaks by killing infected prey which are weaker and thereby easier to capture. However, this proposal warns that predators may sometimes spread disease in host populations. The researchers will use organisms living in lakes to test five ways in which predators could spread disease. These ideas are that predators: (1) while eating prey, physically spread parasites into prey habitat; (2) can increase food supply for prey, and more food can cause higher parasite production within infected hosts; (3) can shift the composition of prey populations towards certain ages and sizes that get infected more easily; (4) can kill other species that control disease; and (5) can cause genetic changes to prey populations, making them more susceptible to disease organisms. The project will focus on water fleas (the hosts), a deadly fungal parasite, and an insect predator to test these possibilities. The research uses these organisms as a model system: outbreaks of this fungus can be sampled in lakes, created in experiments within lakes and in the lab, and can be understood using mathematical models. These new ideas, once tested thoroughly in the lab and verified in nature, will help managers make prudent decisions on how to control disease outbreaks in wild and domestic animal populations. The project will train many students, and focus on engaging those in underrepresented groups. This project integrates three approaches. First, it will invest in a survey of fungal epidemics in water flea hosts in 40 lakes. The data from this large survey will be used to generate complex statistical models that test the first four mechanisms (ideas) given above. Second, it uses controlled experiments. One experiment will test mechanisms (2)-(4) with factorial manipulation of predatory insects and "competitor-diluters" (other water flea species which eat parasite propagules). A second experiment will investigate details of mechanisms (1)-(3). A third experiment investigates a tradeoff among clonal genotypes of the host; genotypes which better escape predation are more vulnerable to parasites. The hypothesis is that predators will shift host populations, via rapid evolution, towards bigger epidemics via this tradeoff. Third, this project develops a new suite of parameterized, mathematical (dynamical) models, designed to evaluate each of the mechanisms separately and together.

疾病生态学家的一个实际目标是找到阻止或减缓感染在宿主之间传播的方法。一种流行的想法是，捕食者通过杀死受感染的猎物来控制疾病的爆发，这些猎物更虚弱，因此更容易捕获。然而，这项提案警告说，捕食者有时可能会在宿主种群中传播疾病。研究人员将使用生活在湖泊中的有机体来测试捕食者传播疾病的五种方式。这些想法是，捕食者：(1)在吃猎物的同时，将寄生虫物理地传播到猎物的栖息地；(2)可以增加猎物的食物供应，更多的食物可以导致受感染宿主内的寄生虫产量增加；(3)可以将猎物种群的组成转向更容易感染的某些年龄和大小；(4)可以杀死其他控制疾病的物种；以及(5)可以引起猎物种群的基因变化，使他们更容易受到疾病有机体的影响。该项目将把重点放在水蚤(宿主)、一种致命的真菌寄生虫和一种昆虫捕食者上，以测试这些可能性。这项研究使用这些生物作为一个模型系统：这种真菌的爆发可以在湖泊中采集样本，在湖泊内和实验室中进行实验创造，并可以使用数学模型来理解。这些新想法一旦在实验室得到彻底测试并在自然界得到验证，将有助于管理人员在如何控制野生和家养动物种群中的疾病爆发方面做出谨慎的决定。该项目将培训许多学生，并专注于让那些代表性不足的群体参与进来。该项目集成了三种方法。首先，它将投资于对40个湖泊中水蚤宿主的真菌流行情况进行调查。这项大型调查的数据将被用来生成复杂的统计模型，以检验上面给出的前四个机制(想法)。其次，它使用了对照实验。一项实验将测试捕食性昆虫和“竞争稀释剂”(其他以寄生虫繁殖体为食的水蚤物种)的因子操纵机制(2)-(4)。第二个实验将研究机制(1)-(3)的细节。第三个实验调查了寄主的克隆基因类型之间的权衡；更好地逃脱捕食的基因类型更容易受到寄生虫的攻击。假设捕食者将通过快速进化将宿主种群转移到更大的流行病上，通过这种权衡。第三，该项目开发了一套新的参数化数学(动态)模型，旨在单独和一起评估每一种机制。

项目成果

Context-dependent host-symbiont interactions: shifts along the parasitism–mutualism continuum

依赖于环境的宿主-共生体相互作用：沿着寄生-互惠连续体的转变

• DOI: 10.1086/716635
• 发表时间: 2021
• 期刊: The American Naturalist
• 作者: Rogalski, Mary Alta;Stewart Merrill, Tara;Gowler, Camden;Caceres, Carla;Duffy, Meghan
• 通讯作者: Duffy, Meghan

Parasite exposure and host susceptibility jointly drive the emergence of epidemics

• DOI: 10.1002/ecy.3245
• 发表时间: 2020-12-27
• 期刊: ECOLOGY
• 影响因子: 4.8
• 作者: Merrill, Tara E. Stewart;Hall, Spencer R.;Caceres, Carla E.
• 通讯作者: Caceres, Carla E.

Variation in Immune Defense Shapes Disease Outcomes in Laboratory and Wild Daphnia

• DOI: 10.1093/icb/icz079
• 发表时间: 2019-11-01
• 期刊: INTEGRATIVE AND COMPARATIVE BIOLOGY
• 影响因子: 2.6
• 作者: Merrill, Tara E. Stewart;Hall, Spencer R.;Caceres, Carla E.
• 通讯作者: Caceres, Carla E.