Mu1-induced mutant alleles of maize exhibit background-dependent changes in expression and RNA processing

We have examined effects of mutations created by transposition of the Mu1 element of maize into genes coding for Adh 1 and Sh 1, by means of allozyme measurements, DNA and RNA hybridization, cloning, and sequencing. From our analysis of mutant alleles we conclude that the element acts both to reduce steady-state levels of RNA and to induce aberrant processing of primary transcripts. We also conclude that genetic background can exert considerable influence in determining the degree to which Mu1 affects these aspects of gene expression.