Abstract: 【Aim】 Bombyx mori inhibitor of apoptosis protein (BmIAP) has been found in the silkworm， B.mori， and characterized as a protein of the IAP (inhibitor of apoptosis protein) family. This study aims to verify its function as a suppressor of apoptosis in B.mori cells， so as to further study the roles of BmIAP in cell apoptosis. 【Methods】 The transient expression vector named PIZ/V5-BmIAP-dsRed was transfected in the BmN-SWU1 cells of B.mori by liposome， and the mRNA and protein expression levels of BmIAP gene were evaluated by real-time quantitative PCR and Western blot analysis， respectively. The BmN-SWU1 cells were induced by 150 ng/mL actinomycin D for 12， 18 and 24 h， and the relationship between BmIAP protein and cell apoptosis was assayed by immunofluorescence and real-time quantitative PCR methods. 【Results】 The PIZ/V5-BmIAP-dsRed vector effectively expressed BmIAP fusion protein of about 60 kD， and the mRNA expression level of BmIAP was up-regulated 45-fold in BmN-SWU1 cells of B.mori. After BmIAP was transiently expressed for 72 h using PIZ/V5-BmIAP-dsRed vector in the BmN-SWU1 cells， BmIAP significantly inhibited the apoptosis in the BmN-SWU1 cells at 12 h after induction by actinomycin D. 【Conclusion】 BmIAP can inhibit apoptosis in B.mori cells and is one of the inhibitor of apoptosis proteins in B.mori.

Key words: Bombyx mori； apoptosis； inhibitor of apoptosis protein(IAP)； eukaryotic expression, transient expression