Analysis of variability among endogenous ecotropic MuLV loci in laboratory mice.
We have isolated a molecular clone of an ecotropic murine leukemia virus from the ovaries of an SWR/J x RF/J hybrid female. The molecularly cloned virus, named pSR3, was demonstrated to induce virus production upon transfection into SWR/J immortalized fibroblasts and to promote germ line integration of proviruses in a fraction of the offspring germline when inoculated to neonate SWR/J females. Sequence analysis reveals that pSR3 is closely related to p623, a plasmid derived from Emv-11 (also referred to as AKV-1). Alignment of the pSR3 sequence with the partial nucleotide sequence of Emv-11 (an endogenous virus carried by BALB/c and C3H/He mice) together with p623 then allows a comparison between three viral sequences. Analysis of these data gives (a) an estimation of the natural divergence rate of MuLV genomes in the course of viral replication (1-5 x 10(-5) mutations per cycle and per nucleotide) and (b) molecular evidence for a recent origin through germ line infection of endogenous loci. From additional clues, Emv-11 appears to be the probable ancestor of at least some of these loci.
Unité de Génétique cellulaire, Institut Pasteur, Paris, France.
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Nouvel
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Philippe
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Condamine
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Panthier
D000483:Alleles; D000818:Animals; D005075:Biological Evolution; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D005260:Female; D005814:Genes, Viral / Q000235:genetics*; D009052:Leukemia Virus, Murine / Q000235:genetics*; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008815:Mice, Inbred Strains; D008969:Molecular Sequence Data; D011533:Proviruses / Q000235:genetics*