Analysis of a controlling-element mutation at the adh locus of maize.

A Ds-suppressed Adh mutant was isolated by the allyl alcohol pollen selection technique. The mutant produces a reduced level of an altered thermolabile enzyme suggesting that the Ds element is inserted in the Adh structural gene. The mutant protein is enzymatically active and does not differ detectably in size from the progenitor protein. A number of possible explanations for the data are presented.