title: DNA polymerases in RNA tumor viruses and possible "protoviruses".
mesh_terms: D000818:Animals; D001358:Avian Sarcoma Viruses / Q000201:enzymology; D002499:Centrifugation, Density Gradient; D002642:Chick Embryo; D004254:DNA Nucleotidyltransferases / Q000378:metabolism*; D004261:DNA Replication; D007074:Immunoglobulin G; D009500:Neutralization Tests; D009858:Oncogenic Viruses / Q000201:enzymology* / Q000472:pathogenicity; D012328:RNA Viruses / Q000201:enzymology; D013698:Templates, Genetic; D014779:Virus Replication
chemical_list: D007074:Immunoglobulin G; D004254:DNA Nucleotidyltransferases