NSF Postdoctoral Fellowship in Biology: Evolution of Increased Parasite Transmission Dispersion

这一行动为NSF 2022财年生物学博士后研究奖学金提供了资金，综合研究调查了基因组、环境和表型之间相互作用的生命规则。该奖学金支持研究员的研究和培训，这些研究员将以创新的方式为生活规则领域做出贡献。这项研究旨在解释被称为传播扩散的流行病中的现象，即大多数新感染病例是由相对较少的感染者传播的。例如，大约10%的新冠肺炎病例是由80%的新冠肺炎新病例引起的。这种差异可能是由于宿主之间的差异，例如，受感染者咳嗽的程度不同。到目前为止，大多数研究都集中在宿主对感染反应的可变性上。然而，病原体本身(例如SARS-CoV-2病毒)也会影响传播扩散。例如，不同的病原体菌株可能会导致不同数量的新感染。病原体传播到的新宿主数量的增加通常是适应性进化的结果(例如，新的SARS-CoV-2变种)。这位研究员假设，当病原体适应不同的宿主群体时，进化也可以增加传播扩散。具体地说，病原体可以适应专门针对高传染性宿主。然而，这可能是以较大但传染性较低的宿主组传播效率较低为代价的。通过这种方式，病原体适应可能会进一步扭曲传播事件，从而使大多数新感染病毒从少数感染宿主传播。这项研究的结果将有助于预测宿主的变异性何时推动高度分散传播的病原体的适应；这将有助于提高预测疫情进程的模型的准确性。此外，该研究员将为费城学校系统的学生开发和教授病原体生态学和进化论的教育模块，目的是增加学生的归属感和对他们的科学能力的信心。这位研究员将通过(1)开发数学模型来生成理论预测，以及(2)使用基于大肠杆菌及其病毒病原体噬菌体Lambda的实验系统测试预测，来确定寄生虫适应是否增加了传播扩散。通过这次培训，研究员将获得基本技能，以建立一个专注于寄生虫进化生态学和流行病学动力学的理论和实验相结合的研究计划。此外，通过向K-12学生开发和教授病原体生态学和进化论的教育模块，将提高该研究员的外展技能，这将增加他们从事科学工作的信心。该奖项反映了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。

This action funds an NSF Postdoctoral Research Fellowship in Biology for FY 2022, Integrative Research Investigating the Rules of Life Governing Interactions Between Genomes, Environment and Phenotypes. The fellowship supports research and training of the Fellow that will contribute to the area of Rules of Life in innovative ways. This research aims to explain the phenomenon in epidemics known as transmission dispersion, where most new infections are transmitted from relatively few infected individuals. For example, roughly 10% of COVID-19 cases cause 80% of new COVID-19 cases. This variation could be due to differences among hosts, for example, in how much infected people cough. Most research to date has focused on variability in host responses to infections. However, the pathogen itself (e.g., SARS-CoV-2 virus) can also impact transmission dispersion. For example, distinct strains of pathogens can drive different numbers of new infections. Increases in the number of new hosts that pathogens transmit to is commonly a result of adaptive evolution (e.g., new SARS-CoV-2 variants). The Fellow hypothesizes that evolution can also increase transmission dispersion when pathogens adapt to variable host populations. Specifically, pathogens could adapt to specialize on highly infectious hosts. However, this might come at the cost of transmitting less effectively from the larger but less-infectious host group. In this way, pathogen adaptation could further skew transmission events so that most new infections are transmitted from a minority of infectious hosts. The study’s results will help to predict when host variability drives the adaptation of pathogens with highly dispersed transmission; this will help to improve the accuracy of models that predict the course of epidemics. In addition, the Fellow will develop and teach educational modules on pathogen ecology and evolution to Philadelphia School System students with the aim of increasing students’ sense of belonging and confidence in their abilities in science. The Fellow will determine whether parasite adaptation increases transmission dispersion by (1) developing mathematical models to generate theoretical predictions and (2) testing predictions using an experimental system based on the bacterium E. coli and its viral pathogen, phage lambda. Through this training, the Fellow will gain essential skills to establish a combined theoretical and experimental research program focused on parasite evolutionary ecology and epidemiological dynamics. Further, the Fellow’s outreach skills will improve by developing and teaching educational modules on pathogen ecology and evolution to K-12 students that will increase their confidence in doing science.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.