Insertional mutagenesis of the maize P gene by intragenic transposition of Ac.
The P-rr allele of the maize P gene regulates the synthesis of pigments derived from flavan-4-ol in the pericarp, cob glumes and other floral organs. We characterized 21 P alleles derived by intragenic transposition of Ac from three known positions. Ac transpositions can occur in either direction in the P gene, and with no apparent minimum distance: in one case Ac transposed just 6 bp from its original insertion site. However, the distribution of transposed Ac elements was markedly nonrandom: of 19 transposed Ac elements derived from a single Ac donor, 15 were inserted in a 1.1-kb region at the 5' end of P, while none had inserted in an adjacent 3.2-kb intronic region. All of the Ac insertions affect both pericarp and cob glume pigmentation, providing further evidence that the P-rr allele contains a single gene required for both pericarp and cob glume pigmentation. The distribution of the inserted Ac elements and the phenotype conditioned by each allele suggests a structure of P-rr which is similar to that previously determined molecularly. Possible explanations for the nonrandom distribution of transposed Ac elements are discussed.
Athma
P
P
Cold Spring Harbor Laboratory, New York 11724.
Grotewold
E
E
Peterson
T
T
D001483:Base Sequence; D003001:Cloning, Molecular; D004251:DNA Transposable Elements; D015870:Gene Expression; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D015183:Restriction Mapping; D013379:Substrate Specificity; D003313:Zea mays / Q000235:genetics*
D004251:DNA Transposable Elements