Studies of mobile elements in maize have made considerable progress in the past few years with the isolation and cloning of several elements and subsequent cloning of a number of genes. This progress is a result of the combined efforts of molecular biologists working closely with geneticists. Early results have elucidated the general structure of the elements, their component parts, and their genetic effects. This work has generated the development of models to explain the role of these elements inducing changes in the genome as well as in individual genes. This project is designed to (a) analyze in En system by isolating mutants controlling the several specific functions of the En element, (b) pursue the genetic analysis of mutable alleles at the C1, C2, A1, A2, Bz, P, and Wx loci in order to isolate mutant derivatives for additional molecular studies, (c) further the studies of the Cy and Uq systems, (d) analyze corn breeding populations for the distribution of mobile elements, and (e) trap master elements at cloned loci for their use in tagging genes. One of the most important developments in modern genetics has been the discovery that chromosomes do not have fixed, static structures, but rather that genes can move from place to place on the chromosomes. The mobility of genes was first demonstrated in corn by Barbara McClintock in the 1950s, and independently by Dr. Peterson not long afterwards. Beginning in the 1970s a large number of investigators began to discover that mobile genes are very widespread in nature; we now know that they are found in almost all species of living organism. Beginning in the late 1970s a number of investigators began to study at the molecular level the mechanisms by which genes move. Dr. Peterson has had a very productive collaboration with Dr. Heinz Saedler (Cologne, FRG) which has resulted in many important contributions to our understanding of these mechanisms. This award will allow Dr. Peterson to continue this collaboration. The mobility of genes has immensely important consequences for the lives of individual organisms, as well as for the evolutionary history of populations. Beyond their intrinsic scientific importance, mobile genetic elements have formed the backbone of many methods of critical importance for biotechnology.
