Construction and characterization of SV40 recombinants with beta-globin cDNA substitutions in their early regions.

A cDNA segment coding for rabbit beta-globin has been inserted at different locations in the early region of simian virus 40 (SV40). The inserted sequences in these recombinants are transcribed from the SV40 early region promoter, and the primary transcripts are processed to mature mRNAs using viral intervening sequences and the early region polyadenylation site. After infection with various recombinants, beta-globin polypeptide is synthesized only when the beta-globin translation initiation codon is the first AUG in the messenger RNA sequence. When the early region transcripts contain the beta-globin cDNA sequence 3-proximal to the small t antigen coding sequence, beta-globin synthesis is not detectable. However, these recombinants produce small t antigen and abbreviated forms of large T antigen.