Temporins are a kind of small,hydrophobic and C-terminus amidated antimicrobial peptides from Rana species.They are effective against bacteria,fungi,yeast,protozoa and viruses.Two novel temporins named as temporin-La(LLRHWKILEKYLanifc) and temporin-Lb(LFRHVVKIFEK.Ylamid.) were cloned from Lithobates catesbeianus.Synthetic peptides of temporin-La and temporin-Lb showed strong antimicrobial activities against bacteria tested,especially Gram-positive bacteria.Besides,temporin-La showed no haemolytic activity to rabbit erythrocytes at the concentration of 250 mg/L while temporin-Lb showed weak haemolytic activity(LC50≈ 230 μmol/L).Transmission electron microscopy showed that temporin-La and temporin-Lb induced different effects on bacterial structure of Staphylococcus aureus.

E2 gene of BVDV Changchun 184 strain was cloned and inserted into the shuttle expression plasmid vector pMV261,the recombinant shuttle plasmid pMV261-E2 was constructed.Then pMV261-E2 was transformed into BCG successfully and obtained recombinant BCG which was resistive to kanamyein.The recombinant BCG were identifieated by PCR.E2 gene expression in recombinant BCG was induced in 45℃,then the SDS-PAGE and western blotting was used to analyze the expression product.The results indicated the BVDV E2 gene was expressd in BCG successfully.