Gammabaculoviruses

Gammabaculoviruses are a genus of double-stranded DNA viruses in the family Baculoviridae, subfamily Baculovirinae. They are one of the four genera in this family; alphabaculoviruses and betabaculoviruses predominantly infect Lepidoptera, while deltabaculoviruses infect Diptera. Gammabaculoviruses infect Hymenoptera, particularly parasitoid wasps, and produce granulovirus-type occlusion bodies that protect virions in the environment.

The viruses have a circular or linear double-stranded DNA genome housed within enveloped virions. Genomes are typically on the order of tens to hundreds of kilobases and contain a set of core baculovirus genes plus genus- or species-specific elements. The occlusion bodies produced by gammabaculoviruses are granular (granuloviruses), which is reflected in the genus name and distinguishes them from polyhedral occlusion bodies seen in some other baculoviruses.

Infection begins when susceptible hosts ingest occlusion bodies, which dissolve in the alkaline gut to release occlusion-derived virions that initiate primary infection of gut or other tissues. This is followed by the production of budded virions that spread the infection systemically within the host. Replication occurs in the host cell nucleus, and later the infection leads to production of new occlusion bodies that are released into the environment upon host death.

Gammabaculoviruses are of interest primarily for basic virology and evolutionary studies within Baculoviridae. Their narrow host range and specialized biology limit their current application as broad biocontrol agents, though they contribute to understanding host–virus interactions and the diversity of baculoviruses in Hymenoptera.