Development of a highly efficient recombinant system for Anticarsia gemmatalis multiple nucleopolyhedrovirus (AgMNPV) and findings about baculoviral replication in absence of the essential gene orf1629

FABRE, MARÍA LAURA; HAASE, SANTIAGO; FERRELLI, MARÍA LETICIA; ROMANOWSKI, VÍCTOR

Tours

Congreso; International Congress on Invertebrate Pathology and Microbial Control, 49th Annual Meeting of the Society for Invertebrate Pathology; 2016

Society of Invertebrate Pathology

Anticarsia gemmatalis multiple nucleopolyhedronvirus (AgMNPV) is one of the most extensively used viral pesticides, but its performance as abiological control agent in more temperate climates requires the improvement of its biopesticidal properties. Genetic modification is a powerfulstrategy to improve these properties in AgMNPV including heterologous genes in the viral DNA. In our laboratory, we have previously developed ahomologous recombination (HR) system to modify AgMNPV genome based on HR in cultured insect cells. Nevertheless, recombinant AgMNPVisolation has proven to be time-consuming. In order to simplify this procedure, we developed a novel recombination system based on a defectiveAgMNPV (AgMNPV-Δ1629) lacking an essential gene (orf 1629) that replicates in a transgenic insect cell line expressing this gene (UFLAg286-1629).By co-transfection of non-transgenic cells (UFLAg286) with parental AgMNPV-Δ1629 DNA and a transfer plasmid (containing orf1629), recombinantbaculoviruses are recovered. HR restoring orf 1629 and allows insertion of pesticidal genes and/or a marker genes under the control of strong viralpromoters. We constructed AgMNPV-Δ1629 and demonstrated the complementation capacity of the transgenic cell line. After this, we tested thesystem by isolating a recombinant virus carrying the green fluorescent protein gene. In addition, novel results were found about the orf1629 geneindicating that baculoviral DNA replicates efficiently in absence of this essential gene and that occlusion bodies appear in transfected cells andconfirmed that this gene is essential for budded virus formation.