ABSTRACT
This chapter summarizes the salient aspects of the literature on nuclear polyhedrosis virus (NPVs) with particular emphasis on developments during the 1980s. The NPV belong to subgroup A of the genus Baculovirus, which, thus far, is the only genus described in the Baculoviridae. Since the mid-1970s an impressive amount of information has accumulated on the replication of the NPVs. Two phases have been defined in the infectious cycle: budded virus (BV) is produced as a result of nucleocapsids, which are assembled in the nucleus, acquiring envelopes at the nuclear or plasma membrane; occluded virus (OV) is produced when one to several nulceocapsids acquire envelopes through a de novo nuclear process and are then occluded into PIBs. This chapter discusses the complex organization of NPVs into OV and BV. It also discusses the biophysical and biochemical properties of polyhedral inclusion bodies (PIBs), polyhedra-derived virions (PDVs), and budded virus.
