THE ENTIRE NUCLEOTIDE-SEQUENCE OF FRIEND-RELATED AND PARALYSIS-INDUCING PVC-441 MURINE LEUKEMIA-VIRUS (MULV) AND ITS COMPARISON WITH THOSE OF PVC-211 MULV AND FRIEND MULV

PVC-441 murine leukemia virus (MuLV) is a member of the PVC group of F riend MuLV (F-MuLV)-derived neuropathogenic retroviruses. In order to determine the molecular basis for the difference in neuropathogenicity between PVC-441 and the previously characterized PVC-211 MuLVs, the e ntire nucleotide sequence of PVC-441 MuLV was determined and compared with those of PVC-211 and F-MuLV. The results suggest that PVC-441 and PVC-211 MuLVs were formed as a result of random mutations of F-MuLV a nd developed differently. The distinct pathogenicities of PVC-441 and PVC-211 MuLVs were maintained in the viruses regenerated from their mo lecular clones, and the sequences responsible for the pathological dif ferences observed can be localized to the env gene. The amino acid seq uence of PVC-441 deduced from its nucleotide sequence revealed a numbe r of differences from PVC-211, the most striking of which was a differ ence at position 129 of the SU proteins in the two viruses. Host range studies with a brain capillary endothelial cell line (RTEC-6) and Chi nese hamster ovary cells (CHO-K1) revealed that PVC-441. Like PVC-211, could infect these cells but its efficiency of infection was lower th an that of PVC-211. These results may account for the difference in ne uropathogenicity between PVC-441 and PVC-211.