The Ac124 protein is not essential for the propagation of Autographa californica multiple nucleopolyhedrovirus, but it is a viral pathogenicity factor.
orf124 (ac124) of AcMNPV is one of the highly conserved unique genes in group I lepidopteran nucleopolyhedroviruses. So far, its function remains unknown. In this study, infection with a virus expressing an ac124-gfp fusion showed that Ac124 localized to the cytoplasm throughout the infection. In addition, an ac124 knockout virus was generated to determine the role of ac124 in the baculovirus life cycle. Our results showed that an ac124 knockout AcMNPV could produce infectious budded viruses (BVs) and occlusion bodies (OBs) like those produced by the wild virus and ac124 repair virus. These three viruses had similar growth kinetics during the infection phase. There was no significant difference in nucleocapsids, occlusion-derived viruses and OBs visualized by electron microscopy. The ac124 deletion mutant did not reduce AcMNPV infectivity for S. exigua in an LD50 bioassay. However, it took 20 h longer for the ac124 deletion mutant to kill S. exigua than wild-type virus in the LT50 bioassay. Altogether, these results demonstrate that ac124 is not required for viral replication, but it accelerates the killing of infected larvae.
College of Bioscience and Biotechnology, Yangzhou University, No. 12 Wenhui Road East, Yangzhou, 225009, People's Republic of China, cyliang@yzu.edu.cn.
Changyong
C
Liang
Dandan
D
Lan
Shuling
S
Zhao
Lulu
L
Liu
Yanan
Y
Xue
Yongli
Y
Zhang
Yun
Y
Wang
Xinwen
X
Chen
D000818:Animals; D002460:Cell Line; D017353:Gene Deletion; D015967:Gene Expression Regulation, Viral / Q000502:physiology*; D049452:Green Fluorescent Proteins; D007814:Larva / Q000821:virology; D017924:Nucleopolyhedroviruses / Q000235:genetics / Q000472:pathogenicity* / Q000502:physiology*; D018411:Spodoptera / Q000821:virology; D014774:Virulence; D014779:Virus Replication / Q000502:physiology*
D049452:Green Fluorescent Proteins