Apoptosis Of Spodoptera Litura Cells Induced By Baculovirus And Preliminary Studies On Its Mechanism

Two apoptotic systems were revealed, microscopic examination of SL-1 cell infected with AcNPV or SfaNPV revealed progressive cell blebbing starting at 8-12 h p.i. and culminating in total cell destruction at 24 h p.i.. The fragmentation of the infected cell nuclei was showed with DAPI. Agarose gel electrophoresis analysis of DNA extracted from infected cells showed typical DNA ladder. All these supported that both viruses infected-SL-1 cells undergo apoptosis.Through lipofectin transfection, only the DNA of AcNPV or SfaNPV can also induce apopotosis of SL-1 cell. Virus titer analysis revealed that neither viruses can duplicate in SL-1 cells. To reveal the mechanism of the apoptosis of SL-1 cell induced by AcNPV more clearly, several chemicals and ie-1 gene were used. When tranfected with iel gene of AcNPV, apoptosis was detected in SL-1 cell by microscopic examination, DAPI staining and DNA ladder. But the same phenomena wasn't observed in Tn-5Bl cell. When treated with chemicals, apoptosis was blocked by monensin and aphidicolin and put off by cycloheximide in contrast to the cells infected with AcNPV without the chemcals.It was revealed for the fisrt time SL-1 undergo apoptosis when transfected with SpltNPV-DNA. Microscope shows cell blebbing starting at 6 h p.i. and culminating in total cell destruction at 18 h p.i. The fragmentation of the infected cell nuclei and apoptotic body were observed by DAPI. DNA extracted from infected cells show typical DNA ladder. All these supported that the transfected SL-1 undergo apoptosis. Neither apoptosis nor polyhedra was observed in SL-1 infected with SpltNPV.Microscopic examination; staining with EB, PI and DAPI; SCGE; electron microscope examination; DNA Ladder and Flow Cytometer were compared and microscopic examination; staining with DAPI; DNA Ladder analysis were adopted to detect apoptosis, by these methods good results were achieved.