Recombination between satellite RNAs of turnip crinkle virus.
Turnip crinkle virus (TCV) is associated with satellite (sat) RNAs (sat-RNA D, sat-RNA F), defective interfering (DI) RNAs (DI RNA G, DI1 RNA), and one RNA with properties of both sat-RNAs and DI RNAs (sat-RNA C). When plants were inoculated with TCV, sat-RNA D and in vitro sat-RNA C transcripts containing non-viable mutations in the 5' domain, recombinant sat-RNAs were recovered. These recombinants were composed of sat-RNA D at the 5' end and sat-RNA C sequences at the 3' end. Analysis of 20 independent recombination junctions revealed that unequal crossing-over had occurred in planta in a region of sequence similarity between the two sat-RNAs which resulted in the duplication of 3-16 nucleotides. Thirty percent of the sat-RNA recombinants also had one to three additional nucleotides inserted at the crossover junctions which did not correspond to either sat-RNA C or sat-RNA D sequence. The right side of the recombination junctions always began with one of three consecutive nucleotides of sat-RNA C. Based on the similarity between this sequence of sat-RNA C, the right side junction of DI RNA G and the 5' end of TCV, as well as the sequence similarity between right side junctions of DI1 RNA and sat-RNA C and the 5' end of the sat-RNAs, a replicase-driven copy choice mechanism is proposed.(ABSTRACT TRUNCATED AT 250 WORDS)
Cascone
P J
PJ
Program in Molecular and Cellular Biology, University of Massachusetts, Amherst 01003.
Carpenter
C D
CD
Li
X H
XH
Simon
A E
AE
D001483:Base Sequence; D002678:Chimera; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009154:Mutation; D010942:Plant Viruses / Q000235:genetics*; D010944:Plants / Q000235:genetics / Q000382:microbiology; D012313:RNA / Q000235:genetics*; D019244:RNA, Satellite; D011995:Recombination, Genetic
D019244:RNA, Satellite; D012313:RNA