title: In vivo generation of hybrids between different species of RNA phages.
abstract: Hybrids between different species or genera of the single-stranded RNA coliphages have not been found in nature. Here, it has been shown that viable hybrids between different phage species can easily be generated in the laboratory by in vivo recombination. cDNA of species I phage MS2 located on a plasmid and lacking part of its 5' untranslated leader (5' UTR) was complemented with another plasmid carrying the 5' half of the genome of fr, a species I phage, or of KU1, a species II representative with low sequence similarity. When the two plasmids were present in the same cell there was spontaneous production of hybrid phages. Interestingly, these hybrids did not arise by a double or single crossover that would replace the missing MS2 sequences with those of fr or KU1. Rather, hybrids arose by attaching the complete 5' UTR of fr or KU1 to the 5' terminus of the defective MS2 phage. Several elements of the 5' UTR then occurred twice, one from KU1 (or fr) and the other from MS2. These redundant elements are in most cases deleted upon evolution of the hybrids. As a result, the 5' UTR of KU1 (or fr) then replaced that of MS2. It was earlier shown that this 5' UTR could assume two alternating structures that facilitated transient translation of the proximal maturation gene. Apparently, this timer function of the 5' UTR was exchangeable and could function independently of the rest of the genome. When hybrids were competed against wild-type, they were quickly outgrown, probably explaining their absence from natural isolates.
authors.affiliation: Leiden Institute of Chemistry, Department of Biochemistry, Gorlaeus Laboratories, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands1.
authors.forename: Dico
authors.initials: D
authors.lastname: van Meerten
authors.affiliation: Leiden Institute of Chemistry, Department of Biochemistry, Gorlaeus Laboratories, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands1.
authors.forename: Herman
authors.initials: H
authors.lastname: Groeneveld
authors.affiliation: Leiden Institute of Chemistry, Department of Biochemistry, Gorlaeus Laboratories, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands1.
authors.forename: David M J
authors.initials: DMJ
authors.lastname: Miller
authors.affiliation: Leiden Institute of Chemistry, Department of Biochemistry, Gorlaeus Laboratories, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands1.
authors.forename: Guillaume B
authors.initials: GB
authors.lastname: Marechal
authors.affiliation: Leiden Institute of Chemistry, Department of Biochemistry, Gorlaeus Laboratories, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands1.
authors.forename: Nina V
authors.initials: NV
authors.lastname: Tsareva
authors.affiliation: Leiden Institute of Chemistry, Department of Biochemistry, Gorlaeus Laboratories, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands1.
authors.forename: René C L
authors.initials: RCL
authors.lastname: Olsthoorn
authors.affiliation: Leiden Institute of Chemistry, Department of Biochemistry, Gorlaeus Laboratories, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands1.
authors.forename: Marcos
authors.initials: M
authors.lastname: de la Peña
authors.affiliation: Leiden Institute of Chemistry, Department of Biochemistry, Gorlaeus Laboratories, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands1.
authors.forename: Jan
authors.initials: J
authors.lastname: van Duin
mesh_terms: D020121:5' Untranslated Regions / Q000502:physiology; D001435:Bacteriophages / Q000235:genetics*; D001483:Base Sequence; D002678:Chimera / Q000235:genetics*; D008969:Molecular Sequence Data; D010957:Plasmids; D012328:RNA Viruses / Q000235:genetics*; D011995:Recombination, Genetic
chemical_list: D020121:5' Untranslated Regions