Population Structure of Schistosomes and Host Snails

描述（由申请方提供）：寄生虫体与其蜗牛宿主之间的相互作用在宿主和寄生虫遗传系统的进化发展中起着重要作用。基因流动、遗传漂变和选择都可能作用于宿主-寄生虫相互作用，驱动共同进化轨迹并决定疾病动态。评估宿主-寄生虫相互作用中两个参与者的遗传异质性的程度和结构是获得流行病学预测能力的重要第一步。曼氏血吸虫和光滑双脐螺的微卫星标记的最近表征提供了一个机会，研究在当地的空间尺度上的宿主和寄生虫的人口结构，使用标记，表现出等位性。具体目标包括：1）基于来自微卫星的等位基因数据确定寄生虫及其蜗牛宿主种群的种群细分的相对性质，并评估遗传变异如何在空间和时间尺度上变化;以及2）将微卫星等位基因异质性与寄生虫毒力和蜗牛抗性的生物标志物相关联，以评估遗传变异与流行病学重要性表型特征之间的关系。了解宿主和寄生虫遗传多样性在个体宿主内和个体宿主之间以及种群内和种群之间的分布，将使我们能够估计寄生虫基因流，评估多基因型对寄生虫毒力的重要性，并开始了解驱动疾病动态的微进化力量的相互作用。结果将产生进化的流行病学过程的见解，帮助确定控制策略的遗传后果，并补充并发的免疫流行病学研究的人在巴西流行的社区。

DESCRIPTION (provided by the applicant): Interactions between schistosomes and their snail hosts play an important role in the evolutionary development of the host and parasite genetic systems. Gene flow, genetic drift and selection all potentially act on host-parasite interactions, driving co-evolutionary trajectories and dictating disease dynamics. Assessing the degree and structure of genetic heterogeneity of both participants in a host-parasite interaction is an essential first step in gaining predictive power over epidemiology. The recent characterization of microsatellite markers for Schistosoma mansoni and Biomphalaria glabrata provides an opportunity to study population structure of both host and parasite on a local spatial scale, using markers that exhibit allelism. Specific aims include: 1) Determine the relative nature of population subdivision for schistosomes and their snail host populations based on allelic data from microsatellites, and assess how that genetic variation changes on both a spatial and temporal scale; and 2) Correlate microsatellite allelic heterogeneity with biomarkers for schistosome virulence and snail resistance to assess the relationship between genetic variation and phenotypic characters of epidemiological importance. Knowledge of the distribution of host and parasite genetic diversity within and among individual hosts, and within and among populations, will allow us to estimate parasite gene flow, assess the importance of multiple genotypes on parasite virulence, and begin to understand the interplay of micro-evolutionary forces that drive disease dynamics. Results will yield evolutionary insights into the epidemiological process, help identify genetic consequences of control strategies, and complement concurrent immuno-epidemiology studies of humans in endemic Brazilian communities.