Fv-1 N- and B-tropism-specific sequences in murine leukemia virus and related endogenous proviral genomes.
Oligonucleotide probes specific for the Fv-1 N- and B-tropic host range determinants of the gag p30-coding sequence were used to analyze DNA clones of various murine leukemia virus (MuLV) and endogenous MuLV-related proviral genomes and chromosomal DNA from four mouse strains. The group of DNA clones consisted of ecotropic MuLVs of known Fv-1 host range, somatically acquired ecotropic MuLV proviruses, xenotropic MuLV isolates, and endogenous nonecotropic MuLV-related proviral sequences from mouse chromosomal DNA. As expected, the prototype N-tropism determinant is carried by N-tropic viruses of several different origins. All seven endogenous nonecotropic MuLV-related proviral sequence clones derived from RFM/Un mouse chromosomal DNA, although not recognized by the N probe, showed positive hybridization with the prototype B-tropism-specific probe. The two xenotropic MuLV clones derived from infectious virus (one of BALB:virus-2 and one of AKR xenotropic virus) failed to hybridize with the N- and B-tropic oligonucleotide probes tested and with one probe specific for NB-tropic Moloney MuLV. One of two endogenous xenotropic class proviruses derived from HRS/J mouse chromosomal DNA (J. P. Stoye and J. M. Coffin, J. Virol. 61:2659-2669, 1987) also failed to hybridize to the N- and B-tropic probes, whereas the other hybridized to the B-tropic probe. In addition, analysis of mouse chromosomal DNA from four strains indicates that hybridization with the N-tropic probe correlates with the presence or absence of endogenous ecotropic MuLV provirus, whereas the B-tropic probe detects abundant copies of endogenous nonecotropic MuLV-related proviral sequences. These results suggest that the B-tropism determinant in B-tropic ecotropic MuLV may arise from recombination between N-tropic ecotropic MuLV and members of the abundant endogenous nonecotropic MuLV-related classes including a subset of endogenous xenotropic proviruses.
Boone
L R
LR
Cellular and Genetic Toxicology Branch, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709.
Glover
P L
PL
Innes
C L
CL
Niver
L A
LA
Bondurant
M C
MC
Yang
W K
WK
D000818:Animals; D004262:DNA Restriction Enzymes; D015683:Gene Products, gag; D009052:Leukemia Virus, Murine / Q000235:genetics*; D051379:Mice / Q000235:genetics*; D009693:Nucleic Acid Hybridization; D009841:Oligonucleotides / Q000235:genetics; D012191:Retroviridae Proteins / Q000235:genetics*; D012689:Sequence Homology, Nucleic Acid; D014779:Virus Replication
D015683:Gene Products, gag; D009841:Oligonucleotides; D012191:Retroviridae Proteins; D004262:DNA Restriction Enzymes