The Autographa californica multiple capsid nucleopolyhedrovirus (AcMNPV) was the first baculovirus for which the complete nucleotide sequence became known. Since then 15 years lapsed and much research has been performed to elucidate putative functions of the annotated open reading frames of this virus and this endeavour is still ongoing. AcMNPV is the most well-known and well-studied baculovirus species, not in the least for its application as a vector for the high-level expression of foreign genes in insect cells. This article is the first monograph of a single baculovirus and gives a current overview of what is known about the 151 AcMNPV ORFs, including (putative) function and temporal and spatial presence of transcripts and protein. To date 60 ORFs have a proven function, another 19 ORFs have homologs for which functions are known in other baculoviruses and 72 ORFs are still enigmatic. This paper should assist the reader in quickly finding the essentials of AcMNPV.
Citation: Cohen David P. A., Marek Martin, Davies Bryn G., Vlak Just M., Monique M. van Oers. Encyclopedia of Autographa californica Nucleopolyhedrovirus Genes[J]. VIROLOGICA SINICA, 2009, 24 (5): 359-414 https://doi.org/10.1007/s12250-009-3059-7
Received: 31 January, 2009; Accepted: 18 May 2009
Data Availability: All relevant data are within the paper and its Supporting Information files.
Funding: The project BACULOGENES of the European Union (LSHB-CT-2006-037541); The Netherlands Scientific Organisation (NWO) MEERVOUD program.
Baculoviruses are viruses of invertebrates that are widely used as biopesticides for the protection of agricultural crops and forests against insect pests (59). This practice has already occurred for over 70 years and these viruses have a perfect safety record to date. More recently these baculoviruses have been used as vectors for the high-level expression of foreign genes (254) and for the transfer of foreign genes into vertebrate systems (40). A most notable characteristic of baculoviruses is the rod-shaped morphology of the virions, hence, the family name Baculoviridae (23). These rod-shaped virions are found occluded in large polyhedral shaped, proteinaceous capsules (polyhedra, 0.1-15 μm in diameter) or in smaller granular capsules (granula) 0.3 till 0.5 μm in length and 0.1 to 0.3 μm in diameter (43). These capsules are often collectively called occlusion bodies (OBs). Baculoviruses share this occlusion phenotype with the genetically unrelated cypoviruses (CPV) and entomopoxviruses (EPV).
The family Baculoviridae comprises four genera, Alphabaculovirus, Betabaculovirus, Gammabaculovirus and Deltabaculovirus (118). The Alphabaculovirus genus contains the nucleopolyhedroviruses (NPVs) of lepidopteran insects and the Betabaculovirus genus encompasses the granuloviruses (GVs) of lepidopteran hosts. The NPVs from hymenopterans form the genus Gammabaculovirus and the Deltabaculovirus genus encompasses the NPVs from dipteran hosts. The Alphabaculoviruses are further divided in group Ⅰ and group Ⅱ NPVs on the basis of phylogenetic analysis (99) and the type of envelope fusion protein (GP64 or F, respectively). The virions of NPVs as found in the occlusion bodies may contain single (S) or multiple (M) nucleopcapsids, but this is not a taxonomical denominator. Collectively about 700 baculoviruses have been described genetically, but only a minority have been characterised to the extent that they can be called a species. Baculoviruses occur in a very wide range of insect hosts, but each virus by itself in general has a narrow host range. The most notable example of a baculovirus with multiple hosts is Autographa californica MNPV, the type species of the Alphabaculoviruses, belonging to the group Ⅰ NPVs.
Baculoviruses have a complex 'life' cycle. They infect their larval host orally and the virions, upon release from the proteinaceous capsules (hence their name occlusion derived virions = ODVs), replicate in the epithelial cells of the larval midgut. Infectious virions (budded virions = BVs) are produced in these cells and released into 