FIG. 2.

Frequency and distribution of SV40 RRs over time in monkeys 21289 and 21306 compared with the SV40 RR obtained from the brain of monkey 18429. The SV40 RR types are numbered 1 to 13 in the order of their sizes as indicated in Fig. 1. Types 5 to 7 and 8 to 10 could not be differentiated by size and are considered together. N indicates the numbers of positive clones analyzed from each sample. W is the number of weeks post SV40 infection. Samples of the brains and kidneys of monkeys 21289 and 21306 were only available at the time of sacrifice. Types 5 to 7 are the most common forms of SV40 RR in the brain of monkey 18429 and gradually became the predominant types in the blood of monkeys 21289 and 21306 over time, as well as in their kidneys and brains at autopsy. Within this group, the type 5 RR is identical to the archetype SV40 RR.