The Relationship Of Microplitis Bicoloratus Bracovirus,Hemichannel And Apoptosis

The Microplitis bicoloratus bracovirus plays a very important role in the inhibition of host innate immunity process. On the other hand, the regulation of hemichannel, one of the main pathways of mass transportation and signal transduction between cells, could have substantial impacts on the physiological function of cells. However, the morphology and genetic composition of MbBV, and the regulatory mechanisms of hemichannel in transferring apoptotic signal during cell apoptosis remain unclear. In this study, we first used cryo-EM to determine the structure of cylindrical nucleocapsid from polydnaviruses. The bracoviruse was shown to have similar cylindrical electron-dense nucleocapsids with variable radii and lengths. Remarkably, we found areas of higher density within the nucleocapsids, presumably representing higher concentrations of viralcoating protein involved in docking at the NPC. These findings provide insights into therelease of dsDNA from docking sides, the top/bottom side within nucleocapsids and also advance our understanding of cylindrical nucleocapsid. Additionally, we extracted and sequenced the DNA of MbBV. A total of 239 DNA fragments and 116 functional genes were obtained and 17 similar circular DNA molecules were assembled successfully. Meanwhile, we sampled the hemocytes cDNA of Spodoptera litura with 7 days post-parasitization and extracted the RNAs of cells with 5 hours post-infection by MbBV. The result shows that, under the action of MbBV, the changes of expression quantities of inxs, p110 expression quantity caused the closure of PI3K/Akt signaling pathway, and that other apoptotic factors promoted the process of apoptosis. Moreover, we used the Bac-to-Bac system to construct N-terminal extensions of inx2 and inx3 viruses in ectopic expression in Sf9. Using Dye uptake and Flow cytometry, we found hemichannel has been turned off with the increase of doses and time; however, the closed hemichannel did not decrease apoptosis, while increased gradually instead. In conclusion, this study highlighted the significance importance of MbBV in hemichannel functions and the process of apoptosis.