Deletions and insertions in adenovirus type 12 DNA after viral replication in vero cells

Abstract

Adenovirus type 12 has been adapted to growth in Vero cells in which there was no evidence for prior infection by SV40 or BK virus. In contrast to the wild type, the adapted virus formed plaques in Vero cells and also replicated in primary African green monkey kidney cells. The DNA of the adapted virus was analyzed by heteroduplex mapping, contour length measurement, and cleavage by the restriction endonucleases Barn HI, Eco RI, and Sma I. The data indicated that replication of adenovirus type 12 in Vero cells resulted in the accumulation of at least five groups of deletion mutants, containing deletions between 0.5 and 1.5 × 10 6 in molecular weight. Plaque purification of the same virus preparations in Vero cells resulted in the loss of most of the deleted molecules and permitted the identification of DNA insertions in fragment E of the Bam HI digest. These insertions ranged between 1.2 and 1.8 × 105 in molecular weight and appeared to represent host cell-specific speuences.