9631967 Walker This work will involve the molecular cloning and characterization of the R-mb complex of maize. The organization of the complex as a whole will be determined through the production of derivatives of the R-mb complex that have lost one or more genes through unequal crossing over. The number, identity and expression of each individual gene of the complex will be determined. The specific regions of the complex involved in paramutagenicity will be determined and a more limited structural characterization of a diverse collection of R geographic alleles will be made. Undergraduate students will be introduced to basic biological research by working on the described projects. %%% Epigenetic inheritance, nuclear inheritance that is not based on DNA sequence, has been recognized in all of the eukaryotic kingdoms. To approach the question of why certain genes are subject to epigenetic regulation while others are not, the structures/sequences of epigenetically regulated genes must be determined. The R paramutation system of corn is ideal for an analysis of this phenomenon because the important components have been localized to the R locus itself and there are a diverse set of alleles with different phenotypes available. Detailed structural analysis of the paramutable R-r complex suggest that a small region of only about two kilobases out of 200 kb is involved in the paramutation process. ***
