Figure 2

Ability of the suppressor cDNAs to restore virus susceptibility to the R4-7 mutant cell line. R4-7 cells were cotransformed with the indicated cDNAs, and the transformants were pooled and grown into cell populations. These cultures were then exposed to equal amounts (approximately 10,000 cfu in NIH/3T3 cells) of an N2 virus preparation, and virus susceptibility was assessed by plating the infected cells in medium containing G418. While the mutant R4-7 control populations yielded only ~50 colonies, the populations expressing the active cDNAs produced nearly confluent lawns. Rat2: virus-sensitive subclone isolated after mutagenesis. R4-7: mutant line. No cDNA: pGKpuro marker DNA alone. Control cDNA: marker plus inactive cDNA. PB1-11, pC1-2: marker plus indicated cDNA.