HEMATOPOIESIS IN SCHISTOSOME-TRANSMITTING SNAILS

这项建议的长期目标是制定一个更全面的 了解软体动物的造血，特别是 传播寄生虫的蜗牛 具体而言，以下问题将 （1）控制血细胞正常产生的因素 光双脐螺（Biomphalaria glabrata）;（2）来源 和B感染后促有丝分裂刺激物的化学性质。 （3）B的生化发育阶段。 glabrata血细胞在造血过程中;和（4）的作用， 造血组织在蜗牛体内相容性。 这项研究可能 更好地了解软体动物的内部防御（免疫） 系统，它直接决定了B的能力。glabrata作为一个 病媒 此外，该项目可能会导致无脊椎动物 用于研究细胞增殖的模型。 利用放射自显影，组织学和超微结构 技术，蜗牛年龄的影响，昼夜节律，以及 将研究细胞周期及其组成阶段的持续时间。 此外，还将建立一个研究造血作用的体外系统。 开发 接下来，将棘口虫和棘口虫幼虫的匀浆 将吸虫注入B。glabrata和促有丝分裂组分将 被隔离和部分特征化。 还有机械创伤的影响 并研究血细胞耗竭。 血细胞个体发育将是 在超微结构水平上进行了研究，使用酶 细胞化学和凝集素探针。 最后是造血的作用 在B中将研究对细菌体感染敏感的组织。 光滑的，其中造血被抑制（通过 δ辐射或秋水仙素）或刺激（通过吸虫相关的 有丝分裂原）。 此外，移植造血组织从 将使用对易感蜗牛有抗性的蜗牛。

The long-term objective of this proposal is to develop a more thorough understanding of hematopoiesis in molluscs, especially schistosome-transmitting snails. Specifically, the following problems will be addressed: (1) factors controlling normal production of hemocytes in the schistosome-transmitting snail, Biomphalaria glabrata; (2) the source and chemical nature of the mitogenic stimuli following infection of B. glabrata by larval trematodes; (3) biochemical stages of development of B. glabrata hemocytes during hematopoiesis; and (4) the role of the hematopoietic tissue in snail schistosome compatibility. This research may lead to a better understanding of the molluscan internal defense (immune) system, which directly determines the capacity of B. glabrata to serve as a disease vector. Furthermore, this project may result in an invertebrate model for the study of cell proliferation. With the use of autoradiographic, histological, and ultrastructural techniques, the effect of snail age, circadian rhythms, as well as the duration of the cell cycle and its component phases, will be investigated. In addition, an in vitro system for studying hematopoiesis will be developed. Next, homogenates of schistosome and echinostome larval trematodes will be injected into B. glabrata, and mitogenic fractions will be isolated and partly characterized. Also, effects of mechanical trauma and hemocyte depletion will be studied. Hemocyte ontogeny will be investigated at the ultrastructural level, with the use of enzyme cytochemistry and lectin probes. Finally, the role of the hematopoietic tissue in susceptibility to schistosome infection will be studied in B. glabrata in which hematopoiesis has been either suppressed (by Delta-irradiation or colchicine) or stimulated (by trematode-associated mitogens). In addition, transplantation of hematopoietic tissue from resistant to susceptible snails will be employed.