Functional genomics of molluscan schistosome development

描述（由申请人提供）：拟议研究的长期目标是鉴定和功能表征调节人类血吸虫曼氏血吸虫幼虫发育的基因。血吸虫在蜗牛中间宿主体内的发育是复杂的，包括几个阶段，包括感染蜗牛的毛蚴、母孢子囊、子孢子囊，最后是感染人类的丝虫。由于毛蚴到母孢子囊的转变被认为涉及从其自由生活到寄生存在的许多生理适应，因此假设这种转变受基因表达中的关键阶段特异性变化的调节。类似地，母孢子囊中无性生殖（胚胎发生）的开始产生多个子孢子囊，以及子孢子囊内尾蚴的形成，被认为涉及通过阶段特异性方式的基因差异表达而协调的发育过程。 然而，到目前为止，很少有人知道有关的身份的基因表达的软体动物幼虫阶段，特别是无性繁殖的孢子囊，并有没有相关的毛蚴母孢子囊到女儿孢子囊阶段的顺序发展的基因表达谱的变化的信息。为了解决这一关键信息 gap，并开始研究幼虫发育是由确定的阶段特异性基因表达变化驱动的假设，提出了以下具体目标：（1）通过使用S. mansoni寡核苷酸基因微阵列;（2）通过测量表达来确认和验证体外DNA微阵列结果 （3）利用基因芯片技术研究钉螺宿主因子对钉螺幼虫寄生体基因表达的影响，并鉴定和鉴定调控钉螺幼虫寄生体基因表达的分子;和（4）使用双功能基因芯片评估发现以幼虫阶段相关方式上调的特定基因是否与定义的发育表型功能相关。单链RNA干扰方法。预计拟议的 微阵列分析方法将填补关于S. Mansoni幼虫阶段相关的基因表达，并将提供重要的见解，在调节发育过程中的特定基因的作用。这项工作的结果可能会导致新的战略 通过破坏特定的幼虫发育依赖基因或其产物来控制蜗牛宿主内的感染。

DESCRIPTION (provided by applicant): The long-term goal of the proposed research is to identify and functionally characterize the genes regulating intramolluscan larval development in the human blood fluke Schistosoma mansoni. Schistosome development within the snail intermediate host is complex, involving several stages including the snail-infective miracidium, mother sporocyst, daughter sporocyst, and finally the human-infective cercaria. Because the miracidium -to-mother sporocyst transition is assumed to involve numerous physiological adaptations going from its free-living to parasitic existence, it is hypothesized that such a transition is regulated by critical, stage-specific changes in gene expression. Similarly, the initiation of asexual reproduction (embryogenesis) in mother sporocysts to give rise to multiple daughter sporocysts and within daughters, the formation of cercariae, is presumed to involve developmental processes orchestrated through the differential expression of genes in a stage-specific fashion. However, to date, very little is known regarding the identity of genes expressed in molluscan larval stages, especially the asexually reproducing sporocysts, and there exists no information on changes in gene expression profiles associated with sequential development from the miracidium to mother sporocyst to daughter sporocyst stages. To address this critical information gap, and to begin investigating the hypothesis that larval development is driven by defined stage-specific changes in gene expression, the following specific aims are proposed: (1) to evaluate gene expression profiles for miracidia and mother sporocysts (early-and late-developing) under in vitro culture conditions by employing S. mansoni oligonucleotide gene microarrays; (2) to confirm and validate in vitro DNA microarray results by measuring expression of specific genes in mother sporocysts developing under in vivo infections conditions; (3) to investigate the effects of snail host factors on larval schistosome gene expression using schistosome gene microarray analyses, followed by identification and characterization of larval expression-modulating snail molecules; and (4) to evaluate whether specific genes found to be upregulated in a larval stage-associated manner are functionally tied to defined developmental phenotypes using double-stranded RNA interference methods. It is anticipated that the proposed microarray profiling approach will fill a critical information gap regarding S. mansoni larval stage-associated gene expression, and will provide important insights into the role of specific genes in regulating the developmental process. Results of this work may lead to novel strategies for controlling infections within the snail host by disrupting specific larval development-dependent genes or their products.