RESUMEN
In order to screen antigenic genes of Clonorchis sinensis (C.sinensis).Firstly,a cDNA expression library from adult worms of C.sinensis was successfully constructed with lambda ZAP express vector.Total RNA of C.sinensis adult worms were extracted by the Trizol reagent and mRNA were further purified through oligo-dT cellulose.The first strand eDNA was synthesized by using MMLV reverse transcriptase.After the synthesis of the second strand,the cDNA were purified by CHROMA SPIN-400 kit and then ligated with lambda ZAP express vector,then packaged in vitro and amplified.The original library contained 1.5 × 106 pfu cDNA clones,the titer of amplified library reached 1.5 × 1010 pfu/mL,in which about 99% clones were recombinants and most of insert DNA fragments were 0.4-2.0 kb.Secondly,immunoscreened using the naturely infected man serum from C.sinensis.The positive clones were sequenced and analyzed.From 2.0 × 105 recombinant clones of the eDNA library,41 positive clones were obtained.Sequence analysis indicated that the cDNAs encoded proteins including glycine rich antigen 2,proline rich antigen 2 and antigen Cs44 from C.sinensis,anothers were lower similarity to predicted protein from Nematostella vectensis,transcription elongation factor GreA from Bartonella quintana str.Toulouse and NM_132090 CG3446 gene product in Drosophila melanogaster from Schistosoma japonicum.These data may form a foundation for identifying recombinant antigens that can be used in the diagnosis or vaccination against clonorchiasis.