Cloning,Expressing Of Schistosoma Japonicum ELAV-like 2 Gene And The Effect On Growing Development

Schistosomiasis caused by schistosomes is an important parasitic zoonosis and mainly occurs in developing countries.Despite decades of control,there are still millions of people at risk of contracting this infection.Eggs produced by the mature female worms are the main factor that cause pathological damage and disease transmission.The study on controlling female reproductive development has great significance in controlling schistosomiasis.In this study,the SjELAV-like 2 gene was amplified by RT-PCR.The recombinant expression vector pET-28(+)/SjELAV-like 2 was constructed by inserting the SjELAV-like 2 gene into the prokaryotic expression vector pET28a.The anti-SjELA V-like 2 serum was prepared after purification of the rSjELAV-like 2 protein.The results showed that the gene length was 1894 bp(GenBank:MG515726),the ORF of SjELAV-like 2 gene was 1635 bp,coding 544 amino acids.The relative molecular weight of rSjELAV-like 2 was 64.2 kDa after combing His-tag,which consistent with the expected result.Western blotting analysis showed that the protein has good antigenicity.Real-time PCR analysis revealed that the gene had the highest expression in schistosomula and tended to be stable after maturation.The expression level of SjELAV-like 2 in the female was significantly higher than that in the male.Its expression in each periods of the male remained maintainance level.Immunohistochemically indicated that the protein is mainly located in the tegument of Schistosoma japonicum.RNA interference was employed to study the biological function of SjELAV-like 2.It was successfully screened S1 siRNA of the best interference effect by RNAi in vivo,which were used for long-term interference experiments of SjELAV-like 2 gene.RT-qPCR shows that RNAi could effectively reduce the expression of SjELAV-like 2 gene in parasites.The long-term RNAi also reduced the hatching rates up to 75.79%(P<0.01)and reduced the liver egg burden to 46.02%(P<0.01).Compared to the negative control,vesicular protrusions significantly increased in the tegumental tissues were observed in SjELAV-like 2 siRNA interference group by scanning electron microscope.These observations implied that SjELAV-like 2 has important influence on growth and development of Schistosoma japonicum,and provides valuable information for the screening of vaccine candidates or new durg target for schistosomiasis.