Signal Transduction relevant to Cherno-klinokinesis of schistosome miracidiai toward intermediate snail host

血吸虫毛虫对中间钉螺(蜗牛条件水：SCW)的分泌物表现出趋化运动。据报道，当某些线虫幼虫的感觉乳头被某些凝集素覆盖时，它们会失去趋势性活动。毛毛虫必须通过它们身体表面的感觉乳头来识别SCW。本研究试图用凝集素结合的方法显示毛虫表面受体的存在。材料和方法：毛滴虫与凝集素的任一末端孵育。然后检查他们的游泳行为和对SCW的趋利性作用。所用凝集素为WGA、PNA、GS-II和MPA。结果和讨论：在所检测的凝集素中，只有高浓度(100 ug/ml)的WGA才能引起行为改变(游泳方向的频繁改变)。250 ug/mlWGA预先孵育10min后，毛虫对SCW无趋化作用。这些结果表明：(1)SCW的受体是前…更多的毛虫被发送到毛虫的身体表面，以及2)当受体被WGA覆盖时毛虫松散的趋化作用。最近，我们报道了cAMP和SCW一样引起毛虫游动方向的频繁变化。然后，试图研究WGA是否能抑制cAMP诱导的毛滴虫行为改变。毛虫经WGA预孵育后，游泳方向发生频繁变化。由于这一结果提示cAMP作为毛滴虫趋化运动信号转导的信使，我们试图验证我们的假说。毛滴虫与降低细胞间eAMP浓度的试剂(MDL-12、330A、SQ 22526、咪唑)或蛋白激酶A抑制剂(PKI(14-22)amid)孵育后，检测它们对SCW的趋化作用。正如预期的那样，这些毛虫确实降低了对SCW的趋化活性。这些结果清楚地表明，cAMP在趋化运动中起重要作用。毛滴虫向SCW的方向。较少

Schistosorne miracidia show chemo-klinokinesis toward the secretions of the intermediate snails (Snail Conditioned Water : SCW). A certain kinds of nematode larvae are reported to loose their chennotactic activity when their sensory papillae are overspread by some kinds of lectin. Miracidia must recognize SCW by the sensory papillae on their body surface. The present study was attempted to show the presence of receptor on the miracidia by using lectin binding. Materials and Method : Miracidia were incubated with any hind of lectin. They were then examined for their swimming behavior and for cheinotactic action toward SCW. Lectin used was WGA, PNA, GS-II and MPA. Results and Discussion : Of lectin examined, only WGA, at high concentration (100 ug/ml), caused the behavior, change (frequent change in swimming direction). And miracidia pre-incubated with WGA, at 250 ug/ml for 10 min, did not show the cherotactic action toward SCW. These results indicate that 1) the receptors of SCW are pre … More sent on the body surface of miracidia, and 2) miracidia loose chemotactic action when the receptors are overspread by WGA. Recently we reported that CAMP induces the frequent change in swimming direction of miracidia as well as SCW does. Then an attempt was made to examine whether WGA inhibits cAMP-induced miracidial behavior change. Miracidia pre-incubated with WGA showed the frequent change of swimming direction. Since this result suggests the role of cAMP as a 2^<nd> messenger of the signal transduction of chemo-klinokinesis of miracidia, an attempt was made to verify our hypothesis. Miracidia were incubated with the reagents that lower the intercellular e_AMP concentration (MDL-12,330A, SQ 22526, imidazole) or inhibitor of protein kinase A (PKI(14-22) amid), and then examined for their chemotactic action toward SCW. As was expected, these miracidia did reduce the chemotacitc activity toward SCW. These results clearly indicate that cAMP plays an important role in chemo-klinokinesis. of miracidia toward SCW. Less