Genetic evidence of Mutator-induced deletions in the short arm of chromosome 9 of maize. II. wd deletions.

Analyses of 113 putative Mutator-induced events involving the yg2 locus of chromosome 9 revealed that 11 of these events were deletions that produce albino seedlings when homozygous. This phenotype is characteristic of wd (white deficiency) deletions. All 11 wd-Mu deletions failed to complement wd1 and pyd1 (pale-yellow deficiency). Nine of the wd-Mu deletions were analyzed cytologically. Two were found to be terminal deletions and seven were internal deletions. Two of the seven had normal pairing throughout the terminal region involved in the pyd1 and wd1 deletions. Because genetic tests established that deletions were present in these two stocks, these deletions were probably too short to disrupt the pairing of the homologous chromosomes. Mechanisms by which the Mutator system might generate these deletions are discussed.