title: Long-term persistence of transformation-defective mutants of subgroup C in chickens and ducks inoculated early in life.
abstract: Three transformation-defective mutants derived from avian sarcoma viruses of subgroup C were injected intraembryonally and neonatally into leukosis-free chickens. Viruses persisted in the blood of all inoculated birds tested for 43 to 163 days after hatching. Similarly, these viruses persisted over more than one year in ducks injected intraembryonally. In two tested ducks virus titres in blood plasma were determined and it was found that they reached 10(2) and 10(3) infectious units per ml. The significance of td mutant persistence, particularly in relation to a possible recombination with chicken and duck src sequences, is discussed.
mesh_terms: D000818:Animals; D001358:Avian Sarcoma Viruses / Q000235:genetics* / Q000302:isolation & purification; D002472:Cell Transformation, Viral; D002645:Chickens / Q000382:microbiology*; D004372:Ducks / Q000382:microbiology*; D005814:Genes, Viral; D014766:Viremia