PARASITIC CASTRATION IN SNAILS--ROLE OF BIOGENIC AMINES

描述：(改编自申请者摘要)：寄生虫 幼虫吸虫对蜗牛的阉割，表现为 性腺的组织病理学改变和/或产卵减少， 代表了一个最戏剧性的例子，说明寄生虫是如何 修改主持人的内部环境以利于他们自己的成长 和繁衍。然而，这种现象的分子基础是 仍然未知。初步研究结果显示，曼氏血吸虫 感染光面蜗牛导致中国人抑郁 产卵和同时在几种寄主水平上的生物性 中枢和/或血浆中的胺，包括L-多巴、多巴胺和 血清素。因为这些生物胺调节其他生物的生殖活动 软体动物，这项研究建议解决了寄生的假设 幼虫血吸虫的去势部分是由于寄生虫的调节 蜗牛宿主生物胺水平或酶的作用 综合。使用分析方法的组合来量化 活体钉螺组织中生物胺水平和酶活性的研究 抑制实验，以及测定生物胺与 寄主生殖器官和幼虫曼氏血吸虫，调查者将 解决四个具体目标：1)确定血吸虫的影响 中枢神经系统(CNS)中生物胺水平的感染， 蜗牛的性腺、白蛋白腺和无细胞血淋巴(血浆) 寄主光滑假单胞菌，2)确定幼虫感染对 参与中枢神经系统生物胺合成途径的酶，3)评估 体内和体外单胺类药物对生殖功能的影响 感染和未感染钉螺的活动，以及4)评估能力 血吸虫幼虫的摄取和代谢或抑制活动 是生物胺的宿主。了解生物胺在蜗牛体内的作用 繁殖和寄生虫如何干扰它们的活动可能导致 以新陈代谢紊乱为基础的生物防治新方法 媒介蜗牛的产卵。

DESCRIPTION: (Adapted from the Applicant's Abstract): Parasitic castration of snails by larval trematodes, which manifests itself as histopathological changes in the gonads and/or lowered oviposition, represents one of the most dramatic examples of how parasites are capable of modifying the host's internal environment to favor their own growth and reproduction. However, the molecular basis for this phenomenon is still unknown. Preliminary findings show that Schistosoma mansoni infection of the snail Biomphalaria glabrata leads to a depression in oviposition and concurrently in the levels of several host biogenic amines in the CNS and/or plasma, including L-dopa, dopamine, and serotonin. Since these bioamines regulate reproductive activity in other molluscs, this research proposal addresses the hypothesis that parasitic castration by larval schistosomes is due in part to parasite modulation of snail host bioamine levels or enzymes responsible for their synthesis. Using a combination of analytical methods to quantify bioamine levels and enzyme activities in snail tissues, in vivo inhibition experiments, and assays measuring bioamine interaction with host reproductive organs and larval S. mansoni, the investigator will address four specific aims: 1) to determine the effects of schistosome infection on bioamine levels in the central nervous system (CNS), gonads, albumin gland, and cell-free hemolymph (plasma) of the snail host, B. glabrata, 2) to determine the impact of larval infection on key enzymes involved in bioamine synthetic pathways in the CNS, 3) to assess effects of in vivo and in vitro monoamine manipulations on reproductive activity of infected and noninfected snails, and 4) to assess the ability of larval schistosomes to take up and metabolize, or inhibit activity of, host bioamines. Understanding the role of bioamines in snail reproduction and how parasites interfere with their activity may lead to novel methods of biological control based on metabolic disruption of egg production in the vector snail.