title: RNA sequencing provides evidence for allelism of determinants of the N-, B- or NB-tropism of murine leukemia viruses.
abstract: Previous genetic and biochemical studies identified three large RNAase T1-resistant oligonucleotides, each associated with either the N-, B- or NB-tropism of murine C-type viruses of BALB/c origin. These oligonucleotides were shown to lie in the 5' third of the oligonucleotide maps of their respective viruses. We sequenced the three oligonucleotides and found that they share a 10 base sequence. Together these observations provide good evidence that the determinants of N-, B- or NB-tropism monitored by the three oligonucleotides are allelic. The oligonucleotides associated with N- and B-tropism differ in sequence at four of sixteen nucleotides, while the B- and NB-tropism-associated oligonucleotides differ in sequence by only one base out of sixteen. These results are consistent with the possibilities that B-tropic viruses may arise from N-tropic viruses by recombination, while NB-tropic viruses may arise from B-tropic virus by mutation. An unexplained finding was that a 10 base sequence present in the oligonucleotide associated with N-tropism is also found in the 3' third of the genomes of the N-, B- and NB-tropic viruses studied.
mesh_terms: D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D009052:Leukemia Virus, Murine / Q000235:genetics*; D051379:Mice; D008815:Mice, Inbred Strains / Q000382:microbiology; D009843:Oligoribonucleotides; D012367:RNA, Viral / Q000235:genetics*; D013045:Species Specificity; D014764:Viral Proteins / Q000032:analysis / Q000235:genetics; D014779:Virus Replication
chemical_list: D009843:Oligoribonucleotides; D012367:RNA, Viral; D014764:Viral Proteins