Abstract—A continuous cell line, designated SENL1, has been established from Spodoptera exigua. The susceptibility of this cell line to its homologous virus, S. exigua multicapsid nucleopolyhedrovirus (SeMNPV), was evaluated on the basis of cytopathic effects, virus replication and morphogenesis in the infected cells. This cell line was highly susceptible to SeMNPV. By 3 days postinfection (pi), 99% of the cells contained occlusion bodies (OBs). Electron microscopy indicated that the OBs of SeMNPV produced in infected SENL1 cells were on average significantly larger than those produced in the infected larvae. Aberrant morphogenic characteristics such as abnormal OB formation and virion occlusion were observed in the SeMNPV-infected cells. A significant reduction in virions and nucleocapsids per OB was noted in the SeMNPV OBs produced in the infected cells when compared with the OBs produced in infected larvae. However, SeMNPV OBs obtained from infected SENL1 cells were infectious for S. exigua larvae, demonstrating that virus replication in vitro yielded viable progeny. The results from the present study suggest that the morphology and biological activity of SeMNPV OBs are influenced by some factors both in host cells and virus interactions. Thus, SENL1 cells may provide an in vitro system for studying possible cell effects on SeMNPV OB morphogenesis and ODV occlusion.

 

Index Terms—Spodoptera exigua, nucleopolyhedrovirus, electron microscopy, virus morphogenesis, insect cell culture

Cite: Sudawan Chaeychomsri, Win Chaeychomsri, Jindawan Siruntawineti, Motoko Ikeda, and Michihiro Kobayashi, "Replication and Occlusion Body Formation of Spodoptera exigua Multicapsid Nucleopolyhedrovirus in a Homologous Cell Line," Journal of Advanced Agricultural Technologies, Vol. 5, No. 3, pp. 236-244, September 2018. Doi: 10.18178/joaat.5.3.236-244