The complete genome of a baculovirus isolated from an insect of medical interest: Lonomia obliqua (Lepidoptera:Saturniidae)

Lonomia obliqua (Lepidoptera: Saturniidae) is a species of medical importance due to the severity of reactions caused by accidental contact with the caterpillar bristles. Several natural pathogens have been identified in L. obliqua, and among them the baculovirus Lonomia obliqua multiple nucleopolyhedrovirus (LoobMNPV). The complete genome of LoobMNPV was sequenced and shown to have 120,022 bp long with 134 putative open reading frames (ORFs). Phylogenetic analysis of the LoobMNPV genome showed that it belongs to Alphabaculovirus group I (lepidopteran-infective NPV). A total of 12 unique ORFs were identified with no homologs in other sequenced baculovirus genomes. One of these, the predicted protein encoded by loob035, showed significant identity to an eukaryotic transcription terminator factor (TTF2) from the Lepidoptera Danaus plexippus, suggesting an independent acquisition through horizontal gene transfer. Homologs of cathepsin and chitinase genes, which are involved in host integument liquefaction and viral spread, were not found in this genome. As L. obliqua presents a gregarious behavior during the larvae stage the impact of this deletion might be neglectable

Structural and ultrastructural changes during the infection of UFL-AG-286 cells with the baculovirus AgMNPV

During infection of the permissive insect cell line UFL-AG-286 by the baculovirus Anticarsia gemmatalis nucleopolyhedrovirus (AgMNPV-2D) several morphological changes occur. By 12 h postinfection (h p.i.), the infected cells became round and exhibited a decrease in the number of cytoplasmic projections. By 24 h p.i., it was possible to detect a virogenic stroma inside the cell nucleus, and after 48 h p.i., polyhedral inclusion bodies were observed. Some of these morphological modifications are probably due to changes in the cytoskeleton of the cell and this possibility was substantiated by the observation that the distribution of actin and microtubules was dramatically modified upon infection. Several viral-induced proteins were also produced during infection and a sharp decrease in overall protein synthesis was observed. These results are very similar to those obtained with other cell lines infected with different baculoviruses, indicating a similar mechanism of infection. Copyright 1998 Academic Press.