A gene map for Biomphalaria glabrata, a S. mansoni host

血吸虫如何在蜗牛宿主中生存或成为毁灭目标的根本问题是 对血吸虫病流行病学的重要意义。前面的基础工作清楚地表明， 光滑蜗牛的遗传变异在软体动物体内的发育中起着重要作用 曼氏血吸虫寄生蠕虫被基因选择为两种寄生虫之一的蜗牛种群 抗性或感病为我们鉴定标记和基因提供了宝贵的资源(S) 在蜗牛/寄生虫的关系中很重要。我们的目标是使用成熟的分子工具，研究 定义了具有稳定但不同易感表型的钉螺种群，以识别和表征那些 在抵抗或完全支持血吸虫感染方面发挥关键作用的蜗牛基因。多态 在抵抗和敏感的蜗牛DNA中，我们应该能够有效地分离出针对这些 涉及蜗牛/寄生虫关系的序列。还将使用检查遗传性的方法 在后代蜗牛中分离抗性或敏感性的多态标记。通过生成 抑制消减杂交(SSH)文库来自暴露与正常、抗性和敏感 通过筛选具有抗性和抗药性的基因探针的蜗牛微阵列 易感幼年蜗牛(+/-寄生虫感染)，我们希望识别控制这些不同的基因 这种钉螺宿主的感染表型。为了利用FISH技术对光肩星天牛染色体进行定位，我们将 使用(作为探针)袋克隆，对应于从微阵列/消减研究中鉴定的转录本。 我们的总体战略是减少重复标记的流入，并将从 DNA和RNA水平，以剖析与寄生虫发育或破坏有关的基因产物 在相对较大的光滑假单胞菌基因组中。

The fundamental issue of how a schistosome survives, or is targeted for destruction, in a snail host has important implications for the epidemiology of schistosomiasis. Preceding groundwork clearly showed that genetic variations in the snail Biomphalaria glabrata play a major role in the intramolluscan development of the parasitic helminth Schistosoma mansoni. Snail stocks that were genetically selected as either parasite resistant or susceptible have provided us with valuable resources for identifying markers as well as gene(s) important in the snail/parasite relationship. Our objective is to use well-established molecular tools, studying defined snail stocks with stable but different susceptibility phenotypes, to identify and characterize those snail genes that play a critical role in resisting, or fully supporting, a schistosome infection. Polymorphisms in resistant vs. susceptible snail DNA should enable us to efficiently isolate probes targeting those sequences involved in the snail/parasite relationship. Use will also be made of examining the heritability of polymorphic markers in progeny snails that segregate for resistance or susceptibility. By generating suppression subtraction hybridization (SSH) libraries from exposed vs normal resistant and susceptible juvenile snails and, by screening an available snail microarray with cDNA probes from resistant and susceptible juvenile snails (+/- parasite infection), we hope to identify genes that govern these different infection phenotypes in this snail-host. For positional mapping of B. glabrata chromosomes by FISH, we will use (as probes) BAG clones, corresponding to transcripts identified from the microarray/subtraction studies. Our overall strategy is to reduce the inflow of repetitive markers and combine useful information gained at both DNA and RNA levels to dissect relevant gene products involved in parasite development or destruction coded for, within the relatively large B. glabrata genome.