Figure 4.

Synthesis of E1A/1B and E4 mRNAs during infection by wild-type and pTP deletion mutant viruses. (A) E1A and E1B mRNAs present within cytoplasmic RNA at various times after infection of HeLa cells with either dl309 or dl308_ΔpTP as indicated above the lanes were analyzed using an antisense probe extending from the BstEII site at 1915 bp (within the E1B gene) to the left end of the chromosome. The antisense probe and the mRNAs are schematically indicated above. Introns within the E1A mRNAs are indicated by dashed lines. The solid arrowhead indicates that the E1B mRNAs continue. An autoradiograph of the gel is presented below with the protected fragments identified. The insertion of a BstBI adaptor at the XbaI site within the E1A 3′ exon of dl308_ΔpTP leads to inefficient cleavage at the site of the discontinuity and results in the dl308_ΔpTP-specific fragment indicated. (B) The relative amounts of E4 mRNA present within cytoplasmic RNA at various times after infection of HeLa and 293 cells with dl308_ΔpTP as indicated above the lanes were analyzed by RNase protection. The antisense probe and the E4 mRNAs are represented schematically above. An autoradiograph of the gel is presented below with the E4 protected band indicated to the right.