Investigation Of Resources Of Biocontrol Of Schistosoma Japonicum In The Poyang Lake Schistosomiasis Epidemic Area In Xingzi County,jiangxi Province And The Distribution Of TRP14 In Different Treated Oncomelania Hupensis

This thesis contains two parts:1.The investigation of the resource of biocontrol of Schistosoma japonicum in Poyang Lake schistosomiasis epidemic area in Xingzi County,Jiangxi Province.We collected the Oncomelania hupensis and the Parasilurus asotus,the final host of Exorchis spp.trematodes,in schistosomasis epidemic area around Poyang Lake,and bring them back to Parasitology Research Laboratory of Xiamen University.By exposure to light,cercariae of some certain trematodes will escape from snails and swim in the water,and then we can observe them through a stereoscope.In this survey,we identify that 676 snails in the total 9768 have been infected with trematode,s larvae.There are 501 snails infected with Exorchis spp.,take 74.11%of infected snails and 5.12%of total snails.Snails infected with Schistosoma japonicum counted 175,taking 25.89%of infected snails and 1.79%of total snails.According to the result,the control of schistosomasis will be a tough task,because of the high infection rate of Schistosoma japonicum and the high infection rate of Exorchis spp.is the good resource in biological control of Schistosoma japonicum.2.The distribution of Thioredoxin Related Protein 14(OhTRP14)in different treated Oncomelania hupensisBased on the previous work,(i)by immunohistochemical and Real Time PCR(RT-PCR),we figure out the distribution of TRP14 in negative Oncomelania hupensis:TRP14 concentrate in the digestive tract(DT),digestive gland(DG)and foot(F).The DT express most TRP14,and the foot express least that concentrate in the edge.(ii)Then we construct A OhTRP 14-Escherichia coli(E.coli)expression system.Compare to OhTRP14 with CPDC,?OhTRP14 with SPDC can not catalyze the break of double strand of insulin,which elucite the first Cys playing fatal role.Treated with RNA interference(RNAi),distribution of TRP14 has no change,but the mRNA level,protein expression level declines and Reactive Oxygen Species(ROS)level rise.Immunofluorescence localization of TRP14 shows that TRP14 locate in cytoplasm of hemocytes in snails.We can make it certain that TRP14 can balance redox state in a cell.(iii)We also check TRP14 distribution,mRNA level,protein expression level and ROS level of different stage oncomelania after infected with Schistosoma japonicum,according to the result,we find that the the longer time after infected,TRP14 mRNA level and protein level elevate.Maybe infected with parasite can change redox state in snails.Also check TRP14 mRNA level,protein level and ROS level of snails infected with Exorchis spp.and double infected with Exorchis and Schistosoma,we figure that snails infected with Exorchis spp.express highest level TRP14,and the second is double infection snails.Both of them higher than snails only infected with Schistosoma japonicum.We can guess that higher ROS level kill Schistosoma japonicum larvae.(V)RNAi treat snails already infected with Exorchis spp.,before infected with Schistsoma japonicum,and found no larvae of Schistosoma japonicum survive.So we guess some certain material secreted by Oncomelania hupensis that stimulated by Exorchis spp.inhibit the development of larvae of Schistosoma japonicum in the double infected snails.