This book is based on a project to completely annotate what is known about the function of the ~150 genes encoded by the genome of the most commonly investigated baculovirus, AcMNPV. Once the annotation was completed (summarized in Chapter 12), the material was organized into a series of chapters integrating the role of the gene products in the biology of major processes central to the replication and pathology of baculoviruses. Chapters on taxonomy, the application of baculoviruses as insecticides, the molecular basis for the remarkable ability of these viruses to express genes at high levels, and the interrelationships of baculovirus and insect retroviruses are also included. The chapters are accompanied by 41 figures, 14 tables and a glossary of common terms used in baculovirology.

Contents

• Preface
  Created: January 26, 2011.
• 1. Introduction to the baculoviruses, their taxonomy, and evolution
  Created: January 26, 2011.
  • The discovery of baculoviruses
  • The definition is not in the name: Naming baculoviruses
  • What defines a baculovirus?
  • Baculovirus Diversity
  • Related viruses: the nudiviruses
  • An occluded virus of pink shrimp, Panaeus monodon
  • A polydnavirus connection
  • Hytrosaviruses and a Whispovirus
  • Related References
• 2. Structural proteins of baculovirus occlusion bodies and virions
  Created: January 26, 2011.
  • Occlusion body evolution
  • Occlusion body proteins
  • Polyhedron associated proteins
  • Baculovirus envelope proteins
  • Nucleocapsid Structure
  • BV and ODV Nucleocapsid associated proteins encoded by all baculoviruses
  • Proteomic analysis of budded virions
  • Proteins associated with ODV that are also likely to be components of BV
  • Other virion associated proteins: ODV associated proteins identified by proteomic analysis
  • References
• 3. The baculovirus replication cycle: Effects on cells and insects
  Created: January 26, 2011.
  • The insect midgut
  • Two types of virions
  • From occlusion bodies to susceptible midgut cells
  • Entry into nuclei
  • Viruses that cause systemic infections (for virus infections restricted to the midgut, see below)
  • Viral proteins involved in the infection cycle
  • Budded versus cell-associated virus — is there a transition?
  • Occlusion, the final stage in virus infection
  • Virus dispersal
  • The cytopathology of GVs
  • Viruses that are confined to the midgut: hymenopteran and dipteran NPVs
  • Persistence/latent baculovirus infections
  • References
• 4. Early events in infection: Virus transcription
  Created: January 26, 2011.
  • Transcriptional activators, enhancers and the host RNA polymerase
  • Baculovirus infection: selective effects on host cell gene expression
  • The baculovirus transcription cascade: the evolution of a novel strategy
  • Transcriptional enhancers
  • Baculovirus enhancers:hrs (homologous regions)
  • A major transcriptional activator of early genes, immediate early gene 1 (IE1, Ac147)
  • Binding of IE1 to hr sequences
  • RNA polymerase II signals regulating early virus gene transcription
  • Genome-wide analysis of baculovirus promoters
  • How are baculovirus early genes activated?
  • Caveats and qualifications
  • References
• 5. DNA replication and genome processing
  Created: January 26, 2011.
  • Identification of origins of viral DNA replication
  • Genes required for DNA synthesis
  • Additional genes that influence DNA replication
  • Baculovirus DNA replication genes: What's missing?
  • Location of baculovirus DNA replication; development of the virogenic stroma
  • Additional baculovirus genes: hints of DNA repair
  • Genes involved in nucleotide biosynthesis
  • How are baculovirus genomes replicated?
  • Implications of recombination-dependent replication: Multiple replication origins, a covalently closed circular genome, and multiple nucleocapsids per envelope
  • Processing and packaging of genome-size DNA
  • More unanswered questions
  • References
• 6. Baculovirus late transcription
  Created: January 26, 2011.
  • Activation of baculovirus late genes
  • Baculovirus late promoter elements
  • Insect virus RNA polymerases and occlusion body protein hyperexpression
  • The baculovirus RNA polymerase
  • The categories of RNA polymerases
  • The relationship of baculovirus RNA polymerase to other RNA polymerases
  • In vitro transcription assays
  • Termination of late mRNAs
  • Very late gene expression
  • Other genes involved in late transcription
  • References
• 7. Baculovirus infection: The cell cycle and apoptosis
  Created: January 26, 2011.
  • Baculovirus infection and the cell cycle
  • Viral synthetic pathways: Induction of a 'pseudo' or ‘viral’ S phase environment
  • Apoptosis and baculovirus infections
  • AcMNPV orf92 (p33) — a link between apoptosis and the cell cycle?
  • References
• 8. Host resistance and susceptibility
  Created: January 26, 2011.
  • The insect immune system: hemocytes, melanization and encapsulation
  • The reaction of host cells to baculovirus infection: evidence from proteomics, microarrays, and expression analyses
  • Other pathways that modulate virus infection
  • Host resistance to baculovirus infection in the midgut
  • Other factors influencing Baculovirus host range
  • Investigations on BmNPV and AcMNPV host range in B. mori and S. frugiperda cells
  • References
• 9. Baculoviruses as insecticides: Three examples
  Created: January 26, 2011.
  • An NPV of the velvet bean caterpillar, Anticarsia gemmatalis: Application in Brazil
  • A granulovirus of the codling moth, Cydia pomonella: Application in North America and Europe
  • An NPV of the cotton bollworm, Helicoverpa armigera: Application in China
  • References
• 10. The evolution of high levels of baculovirus gene expression
  Created: January 26, 2011.
  • Some History
  • Initiating infection: environmental stability and the insect midgut
  • Evolution of a biphasic replication cycle that allowed exploitation of the biosynthetic capacity of insect systems
  • Optimizing the cellular environment: The viral RNA polymerase and the shut down of most viral and host genes late in infection
  • Very late gene (p10 and polyhedrin) activation and transcription
  • A role for gene copy number and nonencapsidated viral DNA
  • Baculovirus gene expression and biotechnology
  • Summary and conclusions
  • References
• 11. Baculoviruses, retroviruses, and insect cells
  Created: January 26, 2011.
  • A baculovirus-associated errantivirus (retrovirus)
  • Errantiviruses in Lepidoptera
  • Relationships between insect retroviruses and baculoviruses: the env gene
  • Cellular homologs of baculovirus F/errantivirus env proteins
  • Features of baculovirus F and insect retrovirus env proteins
  • Additional relationships of insect retroviruses and baculoviruses
  • Are errantiviruses infectious?
  • Does env play a role in errantivirus infectivity?
  • The invasion and amplification of retroelements
  • What prevents retroelements from amplifying continuously?
  • Suppression of transposable elements by DNA and histone methylation
  • Suppression of transposable elements by RNA interference
  • The Argonautes: proteins with RNAse activity that are critical in RNA interference
  • Suppression of transposable elements in gonadal cells
  • In Drosophila: flamenco, a source for piRNAs
  • Summary: unanswered questions
  • References
• 12. The AcMNPV genome: Gene content, conservation, and function
  Created: January 26, 2011.
  • Adjustments to the AcMNPV genome sequence: There are approximately 150 orfs
  • Annotation of the AcMNPV genome
  • References
• 13. Selected baculovirus genes without orthologs in the AcMNPV genome: Conservation and function
  Created: January 26, 2011.
  • References
• Glossary
  Created: January 26, 2010.
• Appendix 1. Sequenced Baculovirus genomes
  Created: January 26, 2010.
• Appendix 2. Common names of insect hosts of baculoviruses that have had their genomes sequenced
  Created: January 26, 2010.