Regulatory mutants of the maize Adh1 gene caused by DNA insertions

Abstract

Transposable elements in maize can induce changes in the timing of gene expression and the quantity of gene product1,2. The timing of expression of the bronze locus has been shown genetically to be affected by insertion of the transposable element Ds (dissociation)3. Molecular evidence has demonstrated that insertion of Ds at another locus, shrunken-1, disrupts the DNA sequence as expected of an insertion4,5. Here we report quantitative changes in gene expression resulting from the insertion of a 1.5-kilobase (kb) DNA element at an affected gene. The alcohol dehydrogenase-1 (Adh1) mutants described here, selected via allyl alcohol-resistant pollen grains6, were recovered from a genetic background containing Robertson's mutator (Mu)7. We suggest that the Mu genetic background caused the DNA insertion at Adh1, and that the insertion assumed some regulatory function in the control of Adh1 expression.