Analysis of protein expression and viral core ultrastructure of wild type and mutant viral particles. A. Viral replication analysis of mutated viruses TCID50 analysis of viral infectivity, scale of ordinate is logarithmic. B. Western analysis of wild type and mutant virus particles C. TEM of late (fixed 36 hr post-transfection) wild type and mutant particles were assessed and scored from multiple sections. Panel I, wild-type virus has typical size and core morphology. Panel II, the pUΔ19 mutant shows diminished production of viral particles, with altered core placement and morphology. Panel III, shows the pDΔ60 mutant; virus particle release less affected; particle condensation to a mature state is impaired. Bar size is .5 μM.