Abstract: Total RNA was extracted from periodic microfilariae of Brugia malayi and its myosin partial gene （Bm-M55） was amplified by RT-PCR. The PCR product was cloned and then subcloned into pcDNA3.1（+）vector. The recombinant eukaryotic plasmids were screened and identified by digestion with restriction enzyme and PCR amplification, and was transfected into COS-7 cells subsequently. The expressed protein was identified by SDS-PAGE. Bm-M55 mRNA was highly expressed in transfected COS-7 cells. The deduced amino acid sequence showed to be identical with that of Bm-M55, and the recombinant protein was about Mr 55 000.

Key words: Brugia malayi, Myosin, Eukaryotic expressing vector, COS-7 cell