FIG. 1.

Emergence of MVMp variants in SCID mice. (A) Infectious titers in three major organs of SCID mice inoculated intravenously with MVMp (10⁷ PFU/mouse), as determined by plaque assay in the NB324K cell line. The mean values and standard deviation from at least three mice per point from two independent inoculations are shown. DL, detection limit of the assay (250 PFU/g of wet tissue). (B) Examples of the heterogeneous plaque size distribution of MVMp variants harvested from mouse organs at two postinfection times. (C) Plaques of all sizes hybridize to a ³²P-labeled DNA probe of MVM genome after overnight exposure.