Genetic heterogeneity of the RNA genome population of the plant virus U5-TMV.
The genetic heterogeneity in a population of the U5 strain of tobacco mosaic virus (U5-TMV) was studied. The T1 fingerprint characterizing a cloned population did not vary after a new cloning step in the local lesion host Nicotiana tabacum Xanthi-nc, nor during four series of 20 passages in the systemic host N. tabacum Samsum. No heterogeneity was observed among 10 clones derived from the cloned populations, while 1 of 18 clones derived from a 20-fold passaged population differed from the rest in 1 of 55 oligonucleotides. A higher heterogeneity was found in an uncloned field isolate in which 2 of 10 clones differed in type in 1 and 2 oligonucleotides, respectively. These data agree with those reported for bacterial and animal RNA viruses and are compatible with the quasi-species model for RNA populations. On the other hand, the intrapopulational heterogeneities found for U5-TMV are considerably smaller than those reported for other RNA viruses, our data showing a high genetic stability for U5-TMV.
Rodríguez-Cerezo
E
E
Departamento de Patología Vegetal, E.T.S.I. Argrónomos, Madrid, Spain.
García-Arenal
F
F
D003001:Cloning, Molecular; D014644:Genetic Variation; D009710:Nucleotide Mapping; D012367:RNA, Viral / Q000235:genetics*; D014027:Tobacco Mosaic Virus / Q000235:genetics*
D012367:RNA, Viral