MOLECULAR ANALYSIS OF THE GENE ENCODING AN ANTIGENIC POLYPEPTIDE OF TRICHINELLA-SPIRALIS INFECTIVE LARVAE

The gene encoding an antigenic polypeptide of Trichinella spiralis infective larvae was studied using recombinant DNA techniques. cDNA synthesized from poly(A)-rich mRNA from T. spiralis infective larvae was ligated into phage vector A.gtl1 DNA and packaged in vitro. The phages were propagated on Escherichia coli and a λgtll expression library was constructed. A cDNA clone encoding a 46 kDa antigenic polypeptide was selected by immunoscreening of the library and identified by the epitope selection method. A clone containing nearly full-length cDNA for a 46 kDa protein was isolated. The gene encoding this 46 kDa antigenic polypeptide was characterized by DNA and RNA blot analysis using the cDNA as a probe. The gene was transcribed to mRNA with approximately 1400 nucleotides and translated to 46 kDa polypeptide. The antigenic polypeptide was excreted/secreted as a 46 kDa native antigen. The antigenic p-galactosidase fusion protein synthesized by bacteria had no cross-reactivity with other parasite-infected sera. © 1990, Cambridge University Press. All rights reserved.