ORF43 (ac43) of Autographa californica multiple nucleopolyhedrovirus (AcMNPV) is a highly conserved baculovirus gene whose function is unknown. To determine the role of ac43 in baculovirus life cycle, we used a new AcMNPV bacmid (bAc-MK) and generated ac43 deletion virus (ac43KO) by using the plasmid capture system (PCS). After transfection into Spodoptera frugiperda cells, ac43KO produced significantly different OBs which with much larger size; and especially had much single nucleocapsids compared to Ac-MK. Furthermore, ac43KO bacmid led to defect in transcription and expression of polyhedrin, which result in less OBs production. However, ac43KO didn't affect BV production since there's no remarkable difference of BV titer in both ac43KO and Ac-MK. These results demonstrate that ac43 play an important role in polyhedrin expression, OB formation, and virion assembly.

• Xue Ying Tao(Department of Agricultural Biotechnology, Seoul National University)
• Jae Young Choi(Department of Agricultural Biotechnology, Seoul National University)
• Yong Wang(Department of Agricultural Biotechnology, Seoul National University)
• Jae Su Kim(Research Institute for Agriculture and Life Sciences, Seoul National University)
• Yeon Ho Je(Department of Agricultural Biotechnology, Seoul National University)