Recombination between viral and cellular sequences generates transforming sarcoma virus

Insights

Recovered avian sarcoma viruses (rASVs) reacquire sarcoma-specific RNA sequences, including novel ones, within the src region. These sequences are crucial for the transforming function of these viruses.

Area of Science:

  • Molecular Biology
  • Virology
  • Oncology

Background:

  • Rous sarcoma virus (RSV) causes tumors and has transformation-defective (td) mutants.
  • Recovered avian sarcoma viruses (rASVs) arise from td mutants and regain transforming ability.

Purpose of the Study:

  • To compare the RNA sequences of rASVs, td mutants, and SR-A RSV.
  • To map the acquired RNA sequences responsible for transforming function.

Main Methods:

  • Oligonucleotide fingerprinting of viral RNA.
  • Comparison of RNA sequences between different virus strains.

Main Results:

  • SR-A RNA contains six sarcoma-specific oligonucleotides; td mutants lack three to six of these.
  • All six rASV isolates regained these six oligonucleotides.
  • Most rASVs possess three new oligonucleotides not found in SR-A or td mutants, located within the src region.

Conclusions:

  • Acquired RNA sequences in rASVs are mapped to the src region and segregate with transforming function.
  • These sequences include both novel and SR-A identical sequences, indicating cellular acquisition and recombination.

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