Published online by Cambridge University Press: 14 April 2009
Three transposable element mutations, displaying an unstable pheno-type at the A locus, were isolated from lines exhibiting Aberrant Ratio behaviour that originated from maize plants treated with plant RNA viruses. Each of these three unstable mutants is shown to belong to the Uq-ruq transposable element system. The two new mutants, along with the previously described a-ruq mutant, are nonautonomous in mutability control in that the control of mutability is governed by the segregating Uq regulatory element. By following the distribution of different Uq elements segregating in independently derived genetic lines and utilizing tests of allelism and linkage, certain lineages of Uq-element-containing lines are revealed.