Mechanism of synthesis of turnip yellow mosaic virus coat protein subgenomic RNA in vivo.
Turnip yellow mosaic virus (TYMV) possesses a monopartite single-stranded (+) sense RNA genome in which the coat protein (cp) gene is 3' proximal and is expressed in vivo via a subgenomic RNA. Evidence is presented here that this subgenomic RNA is synthesized in vivo by internal initiation of replication on (-) RNA strands of genomic length. The double-stranded RNAs (dsRNAs) from TYMV-infected plants have been isolated, purified, and characterized. Under native conditions, no dsRNAs (replicative intermediates and/or replicative forms) of subgenomic length corresponding to subgenomic cp RNA can be detected by ethidium bromide staining of RNA-sizing gels or by Northern blot hybridization using RNA probes. The presence of nascent subgenomic cp (+) RNA strands on the dsRNA of genomic length has been demonstrated using two different approaches: (1) Northern blot hybridization using (-) RNA probes under denaturing conditions and (2) characterization of the 5' ends of nascent (+) RNA strands upon labeling by vaccinia virus nucleoside-2'-methyltransferase.
Institut Jacques Monod, Paris, France.
R
R
Gargouri
R L
RL
Joshi
J F
JF
Bol
S
S
Astier-Manifacier
A L
AL
Haenni
D002213:Capsid / Q000235:genetics*; D005786:Gene Expression Regulation; D005814:Genes, Viral; D066298:In Vitro Techniques; D009029:Mosaic Viruses / Q000235:genetics*; D009693:Nucleic Acid Hybridization; D012330:RNA, Double-Stranded / Q000235:genetics; D012367:RNA, Viral / Q000235:genetics*; D014675:Vegetables
D012330:RNA, Double-Stranded; D012367:RNA, Viral