SCHISTOSOMA JAPONICUM CHINESE STRAIN: CLONING AND EUKARYOTIC EXPRESSION OF THE YOLK FERRITIN GENE

Objective To construct the eukaryotic expressed recombinant plasmid pLYolFer which contains Chinese Schistosoma japonicum Yolk ferritin cDNA, exam its transcript by RNA dot blot, express it in Hela cells and identify its expression condition. Methods The target cDNA fragment was amplified from the adult S. japonicum Chinese strain cDNA library by PCR. RNA dot blot was done and the fragment was ligated into the EcoRⅠ and BamHⅠ site in the vector pLXSN by double restrictive enzymes reaction and linking reaction. The recombinants was transfected into Hela cells using Lipofectamine. The expressed products were examined by SDS-PAGE and Western blot. Results The cDNA fragment was about 600 bp. The recombinant plasmid was constructed successfully. The special expressing product was 21 ku which could be recognized by antibodies in sera of rabbit or mouse infected with S. japonicum. Conclusion The eukaryotic expressed recombinant plasmid pLYolFer which contains Chinese S. japonicum Yolk ferritin cDNA was constructed. It can be used in DNA vaccination further.