POPULATION STRUCTURE OF SCHISTOSOMES AND HOST SNAILS

寄生虫和它们的蜗牛宿主之间的相互作用， 在宿主和寄生虫遗传发育中的重要作用 系统.当地寄生虫的遗传异质性程度 人口对宿主疾病的流行病学有影响。 曼氏血吸虫表现出显著的表型差异， 和地理种群之间，但遗传的程度和性质 这种寄生虫及其宿主蜗牛的变异性仍然存在 大部分未知。现有的多位点DNA标记和 将使用即将推出的单位点分子探针（微卫星） 为了量化宿主和寄生虫遗传异质性的程度， 自然种群;此外，我们将确定这种变化 在空间和时间尺度上的变化。具体目标包括：1） 确定遗传变异如何在各种 每个传播点的寄生虫和蜗牛宿主亚群;以及2） 群体内和群体间相对遗传结构的评估 的数量比较， 化疗后染色体的时间遗传变化。结果 将产生对流行病学过程的进化见解， 确定控制策略的遗传后果，并补充 在这些巴西人中同时进行的人类免疫流行病学研究 社区.

Interactions between schistosomes and their snail hosts play an important role in the development of the host and parasite genetic systems. The extent of genetic heterogeneity in local parasite populations has implications on the epidemiology of host disease. Schistosoma mansoni exhibits significant phenotypic differences within and among geographic populations, yet the extent and nature of genetic variability residing in this parasite and its host snails remains largely unknown. A combination of existing multi-locus DNA markers and forthcoming single locus molecular probes (microsatellites) will be used to quantify the degree of host and parasite genetic heterogeneity in natural populations; further, we will determine how that variation changes on a spatial and temporal scale. Specific aims include: 1) determination of how genetic variation is partitioned among the various parasite and snail host subpopulations at each transmission site; and 2) assessment of relative genetic structure within and between populations of both snail host and schistosomes, and quantitative comparison of temporal genetic changes in schistosomes following chemotherapy. 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 these Brazilian communities.