Baculovirinae

Baculovirinae is a subfamily of the Baculoviridae family, a group of large, enveloped double-stranded DNA viruses that infect insects, particularly lepidopterans. Virus particles are produced in two distinct forms: occlusion-derived virus (ODV), which initiates infection after ingestion of occlusion bodies, and budded virus (BV), which disseminates infection within the host. Occlusion bodies, or OBs, provide environmental protection for virions outside the host.

Genomes of Baculovirinae viruses are circular double-stranded DNA, typically about 80 to 180 kilobases in length and encoding roughly 80–180 genes. Gene expression follows a regulatory cascade with early, late, and very late transcription. Replication occurs in the host cell nucleus. Late in infection, OBs form and house progeny virions, while BVs mediate systemic spread inside the insect.

Classification within Baculovirinae comprises two genera: Alphabaculovirus and Betabaculovirus, which include nucleopolyhedroviruses (NPV) and granuloviruses (GV), respectively, and are mostly associated with Lepidoptera hosts. The broader baculovirus landscape also includes additional lineages placed in other subfamilies. Baculoviruses generally exhibit narrow host ranges and are not known to infect vertebrates.

Applications and significance: Baculoviruses have been developed as environmentally friendly biological insecticides, using NPVs and GVs to control pest insects in agriculture. They are also widely used as expression vectors in biotechnology (the baculovirus expression vector system, BEVS) to produce recombinant proteins in insect cells. In research, Baculovirinae serve as models for studies of virus–host interactions, gene regulation, and protein production.