9406483 Walker Paramutation is defined as an interaction between alleles that leads to directed heritable change at a locus with high frequency. The phenotype is different depending upon which parent transmits the allele. The best studied example of paramutation occurs at the R locus of Zea mays. We will study this system in corn and analyze both the factors that cause a gene to be imprintable and the factors which signal the gene to imprint strongly when next transmitted through pollen. The goal of the work is to initiate a molecular analysis of paramutation. We will determine whether methylation of the locus and decreased production of pigment occur simultaneously and we determine the structures at R/r that are responsible for allowing paramutation and imprinting to occur. %%% Diploid organisms inherit two sets of chromosomes; a maternal set and a paternal set. In most cases, both copies of a gene will function or not in the same way but in a few known cases, the gene from one parent will be expressed and the same gene from the other parent will not be expressed. This phenomenon is known as parental imprinting or paramutation. One of the best studied examples of paramutation is in corn at a locus named R. We will initiate a molecular analysis of this phenomenon in corn and try to determine the mechanisms utilized by the plant. Undergraduate students will participate in the work. A better understanding of genomic mechanisms will be of importance both at the basic and at the applied level. ***
