Mosquito baculovirus: sequence of morphogenesis and ultrastructure of the virion.

The morphogenic sequence of a mosquito baculovirus differed from other baculoviruses in that nucleocapsids ca. 180 nm were formed routinely by cleavage of nucleocapsids as long as 1 microm. Additionally, in one type of envelopment nucleocapsids were enveloped by vesicles which subsequently dissociated. Prior to and during virion occlusion the envelope contracted along two-thirds of the nucleocapsid resulting in the virion being bulbous at one end. The mature virion consisted of an enveloped nucleocapsid with an amorphous, but distinct layer between the nucleocapsid and envelope.