Analysis of mRNA's Transcribed from the Transforming Genes of Human Adenovirus type 12

Adenovirus type 12 mRNA's transcribed from the transforming region in cells transformed by the EcoRI-C (leftmost 16.2%), HindIII-G (leftmost 6.8%) and AccI-H (leftmost 4.7%) fragments of adenovirus type 12 DNA, and in cells lytically infected with adenovirus type 12 were analyzed and mapped on viral DNA by the nuclease S1 mapping and DBM paper blot hybridization techniques. mRNA's were transcribed from the r strand in the transforming region which corresponds to the viral early genes E1A and E1 B. In CY1-1 cells transformed by the -EeoRI-C fragment three E1 A mRNA's and one E1 B mRNA were found, all having spliced structures. GY1-1 cells transformed by the HindIII-G fragment contained three E1 A mRNA's common to GY1-1 cells and two additional E1A transcripts which should be the 3' portions of chimeric mRNA's of cellular-viral and viral-viral sequences. The GY1-1 cells also contained a transcript from the leftmost part of the E1 B gene as the 5' portion of chimeric mRNA species. HY1-5 cells transformed by the AccI-H fragment, which carries only the E1A gene, contained three E1 A mRNA's identical to those found in the CY1-1 and GY1-1 cells. These results indicate that the E1 A gene function alone can produce incomplete transformation phenotypes, and that the E1 B gene function necessary for complete transformation is coded for in the leftmost part of the E1 B gene transcribed into GY1-1 specific chimeric mRNA's The chimeric mRNA species, which were not found in CY1-1 cells nor in cells lytically infected with adenovirus type 12, also suggest the presence of tandemly integrated viral DNA as their trans criptional template in GY1-1 cells. The coding regions for and the sizes of candidate viral proteins responsible for cell transformation were estimated on the basis of the above results and the nucle otide sequence of the E1 A and E1 B genes of adenovirus type 12 DNA determined recently