Systematic Analysis of 42 Autographa Californica Multiple Nucleopolyhedrovirus Genes Identifies An Additional Six Genes Involved in the Production of Infectious Budded Virus

Baculoviruses have been widely used as a vector for expressing foreign genes.Among numerous baculoviruses,Autographa californica multiple nucleopolyhedrovirus(AcMNPV)is the most frequently used and it encodes 155 open reading frames(ORFs).Here,we systematically investigated the impact of 42 genes of AcMNPV on the production of infectious budded viruses(BVs)by constructing gene-knockout bacmids and subsequently conducting transfection and infection assays.The results showed that among the 39 functionally unverified genes and 3 recently reported genes,36 are dispensable for infectious BV production,as the one-step growth curves of the gene-knockout viruses were not significantly different from those of the parental virus.Three genes(ac62,ac82 and ac106/107)are essential for infectious BV production,as deletions thereof resulted in complete loss of infectivity while the repaired viruses showed no significant difference in comparison to the parental virus.In addition,three genes(ac13,ac51 and ac120)are important but not essential for infectious BV production,as gene-knockout viruses produced significantly lower BV levels than that of the parental virus or repaired viruses.We then grouped the 155 AcMNPV genes into three categories(Dispensable,Essential,or Important for infectious BV production).Based on our results and previous publications,we constructed a schematic diagram of a potential mini-genome of AcMNPV,which contains only essential and important genes.The results shed light on our understanding of functional genomics of baculoviruses and provide fundamental information for future engineering of baculovirus expression system.

Inactivating SARS-CoV-2 by electrochemical oxidation

Fully inactivating SARS-Co V-2, the virus causing coronavirus disease 2019, is of key importance for interrupting virus transmission but is currently performed by using biologically or environmentally hazardous disinfectants. Herein, we report an eco-friendly and efficient electrochemical strategy for inactivating the SARS-Co V-2 using in-situ formed nickel oxide hydroxide as anode catalyst and sodium carbonate as electrolyte. At a voltage of 5 V, the SARS-Co V-2 viruses can be rapidly inactivated with disinfection efficiency reaching 95% in only 30 s and 99.99% in 5 min. Mass spectrometry analysis and theoretical calculations indicate that the reactive oxygen species generated on the anode can oxidize the peptide chains and induce cleavage of the peptide backbone of the receptor binding domain of the SARS-Co V-2 spike glycoprotein, and thereby disables the virus. This strategy provides a sustainable and highly efficient approach for the disinfection of the SARS-CoV-2 viruliferous aerosols and wastewater.