Molecular Cloning and Structural Characterization of the R Locus of Maize: Annual Progress Report for Period September 29, 1986-September 28, 1987

摘要

Last year we reported on the isolation of a molecular clone of the R locus of maize using an Ac transposon tagging strategy. During the past year we have confirmed the identity of this clone and have begun a molecular analysis of several R alleles. Our main focus continues to be on the analysis of R-r, an allele containing both seed (S) and plant (P) components. Genomic blot analysis and gene cloning experiments suggest that the R-r allele may be organized as a triplication. In addition to (P) and (S), there appears to be a third cryptic component we refer to as (Q). We are attempting to clone the complete R-r allele by chromosome walking techniques to determine the molecular organization of R-r. The second objective of our research on R is to understand the mechanism of tissue-specific regulation of anthocyanin. We are characterizing several R alleles that condition different pigmentation patterns in plant and seed tissues. In order to determine the allelic differences among tissue-specific components we have obtained genomic clones and are performing DNA sequence analysis to regions of several tissue-specific components that may be responsible for these allelic differences. 1 ref. (ERA citation 12:045232)