Abstract
It was previously suggested that the character of the A-type inclusion can be separated into two markers: the capability to include mature progeny virions within or on the inclusion body (V), and the formation of ground substance of the inclusion body (In). In addition, another difference in the susceptibility to the L cells was found between the vaccinia IHD strain virus and the CPR-Cl cowpox virus (L). The low growth rate of CPR-Cl virus calculated about 3 logs can be rescued by vaccinia IHD virus in mixedly infected L cells.
The recombinants among these markers were found in variable percentages of the progeny viruses of mixed infection with a combination of vaccinia IHD and cowpox CPR-Cl viruses, using the plaque types as control markers. Especially our prediction that the phenotypes of the A-type inclusion is controled by two viral genes was proved by the appearance of V+In+ recombinants of 1.8%. Concerning the plaque types being of polygenic nature, morphological features of cytopathic effect in HeLa cells were coincided with plaque types of all recombinant clones.
