Isolation and characterization of a gp 70+ non producer Friend tumor cell clone.
Viral expression was analyzed in ten cell clones of a Friend erythroleukemia cell line (HFL/b cell line [3]), which had lost its capacity to produce infectious particles. All the ten subclones were non producers but expressed spleen focus forming virus (SFFV) polypeptides in the form of p48-p50gag and gp50-gp52env. One subclone (subclone 9) expressed the gp70env of the Friend-MuLV helper component of the Friend virus complex. Comparative analysis of viral RNA expression in one gp70- subclone (subclone 2) and in the gp70+ subclone (subclone 9) was performed using specific ecotropic env gene probe and MCF/xenotropic env gene probe. In both subclones 2 and 9, the MCF/xenotropic env gene probe detected 32S SFFV genomic RNA, 20S SFFV env gene mRNA and a 34S RNA. The ecotropic env probe failed to characterize any 38S F-MuLV genomic RNA in both clones but detected 34S RNA and 24S env mRNA in the gp70+ subclone 9. These data show that expression of a complete F-MuLV genome is not required for synthesis of env gene products.
D000818:Animals; D002460:Cell Line; D002469:Cell Separation; D002999:Clone Cells / Q000032:analysis; D005622:Friend murine leukemia virus / Q000235:genetics*; D005786:Gene Expression Regulation; D007942:Leukemia, Experimental / Q000235:genetics*; D012367:RNA, Viral / Q000378:metabolism; D014764:Viral Proteins / Q000096:biosynthesis*
D012367:RNA, Viral; D014764:Viral Proteins