Abstract: Objective To clone and express Schistosoma japonicum myosin regulatory light chain （SjMRLC） in prokaryotic expression system and analyze its stage-specific transcription. Methods The recombinant plasmid was constructed with pGEX 4T-3 vector and expressed in BL21. The recombinant SjMRLC was identified through Western blotting assay. Total RNA from different stages of Schistosoma japonicum was extracted and used to detect the stage-specific transcription of SjMRLC. Results The recombinant plasmid of pGEX 4T-3/SjMRLC was constructed correctly. The recombiant protein (rSjMRLC) with GST tag was soluble. SjMRLC showed similar transcription level in all stages including sporocyst, miracidium, egg, cercaria, schistosomulum, female worm, male worm, and paired adults. Conclusion The soluble recombinant protein SjMRLC with GST tag was obtained. SjMRLC is a house-keeping gene.

Key words: Schistosoma japonicum, Myosin regulatory light chain, Clone, Expression, Stage-specific transcription