Transcription map for adenovirus type 12 DNA

Area of Science:

• Molecular Biology
• Virology
• Genomics

Background:

• Adenovirus type 12 (Ad12) gene expression involves distinct early and late phases.
• Understanding the precise genomic locations of RNA transcripts is crucial for deciphering viral replication and pathogenesis.

Purpose of the Study:

• To map the adenovirus type 12 genome regions responsible for producing l- and r-strand-specific cytoplasmic RNA.
• To characterize the temporal expression patterns of Ad12 viral RNA during infection.

Main Methods:

• Hybridization of radioactive, separated complementary DNA strands of the Ad12 genome with unlabeled late cytoplasmic RNA.
• Purification of RNA-complementary DNA segments using S1 nuclease digestion.
• Mapping of coding regions by hybridizing probes to restriction enzyme (EcoRI, BamHI, HindIII) digested Ad12 DNA fragments.

Main Results:

• The Ad12 genome map for RNA coding regions is highly similar to that of adenovirus type 2.
• Early cytoplasmic RNA primarily mapped to the r-strand (EcoRI-C, BamHI-B) and l-strand (BamHI-E), with some hybridization to BamHI-C.
• Late in infection, newly synthesized cytoplasmic RNA predominantly originated from DNA sequences between 25 and 60 map units.

Conclusions:

• Established a detailed map of Ad12 cytoplasmic RNA coding regions.
• Demonstrated distinct genomic origins for early and late viral RNA transcripts.
• Provided insights into the temporal regulation of Ad12 gene expression.