Developmental potency of larval Schistosoma mansoni, and extraction of its mRNA

本研究主要是为了了解如何匹配蜗牛幼虫的发育，从而能够获得有关的mRNA。从感染蜗牛的肠道中分离大量孢子囊的新方法是在25℃条件下，将被感染蜗牛的肠道自溶12 ~ 24小时，用0.3%的生理盐水将感染蜗牛的孢子囊植入到未感染蜗牛中，几乎没有发现蜗牛被感染（0 ~ 0.03%，阳性率）。施耐德果蝇培养基的感染率为31.3- 55.6%。提示培养基等异物影响孢子囊着床时的感染率。在塑料载玻片上用相衬光学技术研究了被副带棘孔虫感染的M系生物螺，或年龄和大小匹配的对照螺的循环血细胞。完全扩散的粒细胞、部分扩散的粒细胞、透明细胞、圆形细胞一致存在。在对照螺中，圆形细胞的相对百分比和估计数/mm3随螺大小的增加而显著下降，两种粒细胞的相应值均增加。感染后8 d，感染螺的圆形细胞和部分扩散的颗粒细胞的相对百分比显著高于对照组。感染钉螺的血细胞吞噬活性明显低于对照组。这些结果表明，如果蜗牛对寄生虫的敏感性受到血细胞数量的影响，那么可以利用血细胞来匹配蜗牛幼虫的发育。

This studies have been undertaken to mainly know way to match larval development in snails thus capable of obtaining mRNA concerning.A new method for isolation of a large number of sporocysts from intestine of infected snails should have process of digestion by autolysis of intestine removed from infected snails for 12-24 hours at 25 'C.When 0.3 % saline was used for implantation of sporocysts from infected to uninfected snails, snails becoming infected were hardly found (0-0.03 %, positive rate). On contrast, 31.3-55.6 % became infected when Schneider's Drosophila medium was used. These findings indicated that foreigh objects such as medium affected infection rate in implantation of sporocysts. Circulating hemocytes from Echinostoma paraensei-infected M line Biomphalaria snails, or from age and size matched control snails, were studied on plastic slides with phase contrast optics. Fully-spread granulocytes,partially-spread granulocytes, hyalinocytes, round cell were consistently present. Among control snails, the relative percentage and estimated number/mm3 of round cells decline significantly with increased snail size, and the corresponding values for both granulocytes increased. By 8 days post infection, infected snails had significantly higher relative percentage of round cells and partially-spread granulo cytes than control. Phagocytic activity of hemocytes was signi-ficantly lower in infected snails than control. These findings indicated that if susceptibility of snail to parasite was affected by hemocyte population, hemocytes could be used to match larval development in snails.