Characterization of the 49 kDa Excretory-secretory Protein Trichinella Native and Trichinella Spiralis

摘要

The gene encoding the 49 kDa excretory-secretory ( E-S) protein ( P49) was amplified by RT-PCR from RNA of Trichinella spiralis and Trichinella nativa and several Chinese Trichinella isolates of domestic animals, and sequenced after being cloned. The target genes of these parasites were all about 950bp in length. The 97. 2% to 100% nucleotides homology and 94. 3% to 100% homology of deduced amino acids among P49 gene of these Trichinella strains showed the close relatedness of these parasites. The P49 gene of Chinese Trichinella strain of dog-origin (TSCD) is completely identical to that of the T. Nativa spiralis identified previously , confirming that the TSCD was T. nativaspiralis. The P49 gene of T. nativa was cloned into the BamHI site of the prokaryotic expression vector pET-30a, and the recombinant vector was expressed. The expressed product was 40. 8 kDa in size. In Western blot a-nalysis, the expressed product was reactive to sera of mice infected with T. nativa, T. spiralis and their Chinese geographical strains.