In vitro synthesis of a 2.1 x 10(6) dalton DNA in the endogenous retrovirus reverse transcriptase reaction

Viral DNA synthesized in vitro by avian retrovirus particles permeabilized with melittin. I. Kinetics of synthesis and size of minus- and plus-strand transcripts

We have examined the kinetics of synthesis of minus [(-)]- and plus [(+)]-strand viral DNA in melittin-permeabilized avian retrovirus particles. The reaction was biphasic. There was a very rapid initial rate, followed, after approximately 1 h, by a lower rate. Many discrete bands of subgenomic-length (-) strands were produced after 10 and 20 min of synthesis; genome-length (7.7-kilobase [kb]) (-) strands were detected within 30 min. Extension to an 8.0-kb (-)-strand species was evident by 60 min. This extension was inhibited by actinomycin D. Synthesis of (+) strands (which is also inhibited by actinomycin D) began early, before any (-) strands were completed, and continued for more than 4 h beyond the time when synthesis of full-length DNA had terminated. Two distinct species of (+)-strand DNA, 0.27 and 0.35 kb, could be observed at the earliest times. Their presence was quickly obscured by subsequent formation of (+)-strand molecules of molecular length between 0.2 and 2.0 kb.

Enrichment of C-type virus mRNA from immunochemically separated polyribosomes

A method for the isolation of mRNA from a c-type virus-positive cell (JLS-V6) has been developed. This method consisted of (i) specific immunochemical precipitation of polyribosomes synthesizing viral proteins, (ii) extraction of the mRNA from the polyribosome/antigen/antibody complex, and (iii) separation of poly-A containing RNA by affinity chromatography on oligo-d(T)-cellulose. Three size classes of virus specific poly-A containing mRNA are identified and they are 35S, 20S-25S, and 10S-15S.