Heterologous recombination in the double-stranded RNA bacteriophage phi 6.
Bacteriophage phi 6 contains three double-stranded RNA genomic segments. We have constructed a virus with an insertion of a kanamycin resistance gene in genomic RNA segment M. The virus forms small, turbid plaques, and its genome is unstable. Virus from a single plaque contained from about 0.1 to 10% large clear-plaque forms of the virus; these were usually missing the kanamycin resistance gene, and in many cases, the resulting segment M was larger or smaller than its normal size. Sequence analysis of the genomic RNA of the apparent deletions showed that they were formed by recombination events between segment M and either segment S or L. These heterologous recombination events resulted in the loss of the kanamycin resistance gene from segment M and the replacement of the 3' end of segment M with the 3' end of segment S or L. Although the 3' ends of the single-stranded RNA transcripts of the genomic segments appear to have extensive secondary structure, the sequences at the 3' ends are not involved in the specificity of genomic packaging.
Mindich
L
L
Department of Microbiology, Public Health Research Institute, New York, New York 10016.
Qiao
X
X
Onodera
S
S
Gottlieb
P
P
Strassman
J
J
D001483:Base Sequence; D003001:Cloning, Molecular; D003434:Crossing Over, Genetic; D016679:Genome, Viral; D007613:Kanamycin Resistance / Q000235:genetics; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009690:Nucleic Acid Conformation; D010641:Phenotype; D012317:RNA Phages / Q000235:genetics*; D012330:RNA, Double-Stranded / Q000235:genetics*; D011995:Recombination, Genetic; D015183:Restriction Mapping
D012330:RNA, Double-Stranded