Evolution of Virulence in Structured Populations

寄生虫面临着一个有趣的权衡。它们利用宿主为生，但过度利用可能导致宿主在寄生虫传播之前死亡。研究小组将验证这样一个假设，即当宿主受到遗传多样性寄生虫的多重感染时，寄生虫之间的竞争选择了更积极的宿主利用和更大的毒力，而宿主内的寄生虫是遗传相关的。研究人员正在通过实验控制寄生虫在宿主中的传播速度，从而改变宿主内寄生虫的亲缘关系。经过20代的选择，研究人员将检查来自低亲缘关系处理的寄生虫是否比来自高亲缘关系处理的寄生虫更具攻击性。这种寄生虫是一种感染昆虫的线虫，已被用于生物防治。该团队还将研究线虫共生细菌的抗菌特性的变化。这项工作将通过测试将进化分析纳入对抗传染病的关键理论，从而使整个社会受益。此外，它将增加我们对农业和潜在的药学上重要系统的认识。该工作每年提供1名全职博士后研究员的薪金和4名本科生的实习机会，为期三年。

Parasites face an interesting tradeoff. They exploit their hosts for their livelihood, yet over-exploitation can result in host death before the parasite is transmitted. The research team will test the hypothesis that, when hosts are subject to multiple infections by genetically diverse parasites, competition among the parasites selects for more aggressive host exploitation and greater virulence than when the parasites within a host are genetically related. The researchers are experimentally manipulating the dispersal rate of parasites among hosts, thereby altering the relatedness of parasites within hosts. After 20 generations of selection, the researchers will examine whether parasites from the low-relatedness treatment have become more aggressive than parasites from the high-relatedness treatment. The parasite, Steinernema carpocapsae, is an insect-infecting nematode, which has been used for biological control. The team will also examine variation in the anti-bacterial properties of a symbiotic bacteria of the nematodes.This work will benefit society in general by testing key theory incorporating evolutionary analysis into combating infectious disease. Additionally, it will increase our knowledge of an agriculturally, and potentially pharmaceutically, important system. This work will also provide salary for one full-time post-doctoral researcher and internships for four undergraduates each year for three years.