New case of c-src gene transduction: the generation of virus PR2257.
PR2257 is a new replication-defective avian sarcoma virus which harbours in addition to the spliced version of the c-src gene also about 950 bp of no-coding cellular sequences located downstream from the c-src stop codon (Geryk et al., 1989). Comparison of the 950 bp region transduced by PR2257 with the chicken c-src cDNA (Dorai et al., 1991) and genomic sequences of the c-src 3' non-coding region from chicken and quail has shown that there are no additional introns. The c-src 3' non-coding region represents the largest c-src exon (No. 12) comprising about 2 kb. Absence of conserved open reading frames within this region in chicken and quail genomic DNAs excludes the possibility for coding a protein by these sequences. Also, the possibility was excluded that numerous endogenous virus-derived sequences identified in molecularly cloned PR2257 provirus played a role in the c-src transduction. After serial passaging of PR2257 virus in vivo a variant PR2257/16 was isolated. In PR2257/16, the size of the env gene was increased due to homologous recombination with a helper virus. In addition to mutations in the viral leader and the v-src coding region, a large deletion in transduced c-src 3' non-coding sequences was found in the PR2257/16 genome. The significance of genome modifications for selective advantage of this viral variant in vivo is discussed.
Dezelee
P
P
Unité de Recherche Associée 1443 du Centre National de la Recherche Scientifique, Institut Curie, Orsay, France.
Barnier
J V
JV
Briest'anská
J
J
Geryk
J
J
Karakoz
I
I
Michailik
A A
AA
Nehyba
J
J
Yatsula
B A
BA
Rynditch
A V
AV
Calothy
G
G
D000818:Animals; D001358:Avian Sarcoma Viruses / Q000235:genetics* / Q000378:metabolism; D001483:Base Sequence; D005814:Genes, Viral; D016391:Genes, src; D006801:Humans; D008969:Molecular Sequence Data; D014161:Transduction, Genetic