Objective: To study the function of Mago nashi gene in reproductive system of Schistosoma japonicum.
Methods: dsRNA products of SjMago nashi gene and control gene (lacZ) were generated by in vitro transcription. SjMago nashi dsRNA and control (lacZ) dsRNA were electroporated into mechanically transformed schistosomula. Aliquots of parasites (1000) were harvested at day 1, 3, and 5 after electroporation, respectively. Total RNA and proteins were isolated simultaneously using TRIzol reagent. Levels of SjMago nashi mRNA and protein were determined by RT-PCR and Western blotting analysis, respectively. About 1000 dsRNA-electroporated schistosomula were injected into each BALB/c female mouse. Six weeks later the worms were collected, fixed, stained, clarified, dehydrated and mounted. The male and female reproductive organs were observed and measured under the confocal laser scanning microscope.
Results: At day 1, 3 and 5 post-electroporation, 22%, 69%, and 80% reduction in Mago nashi mRNA levels were detected respectively in SjMago nashi dsRNA-electroporated schistosomula (experiment group) compared to parasites treated with control dsRNA (control group); and schistosomula of experiment group exhibited 12%, 39%, and 56% decreased in Mago nashi protein expression levels in comparison to the control group, respectively. In experiment group there were many spermatozoa in testicular lobes and no changes were observed in ovary and vitelline gland. Compared to control group, adult worms in experiment group were smaller in the body width, the width and length of testicles and ovaries (P < 0.05).
Conclusion: Mago nashi dsRNA can specifically inhibit the expression of target gene and protein. SjMago nashi gene is a reproduction-related gene.