The long range objective of this research proposal is to determine the molecular mechanisms that govern gene transmission during meiosis. Although this process plays a central role in the generation of genetic variation and the production of gametes with normal chromosome numbers, relatively little is known at the molecular level about the specific genes required for these events. The simple eucaryote, S. cerevisiae, is being used in these studies. The experimental program is specifically aimed at providing a molecular description of the structure, function and regulation of three genetically well-defined genes, SP011, SP012 and SP013, known to have important roles in meiotic chromosome behavior, as well as a fourth gene, SP016, which is closely linked to SP012 and is required for optimal levels of spore formation. The SP011 gene is necessary for meiotic recombination while SP012 and SP013 are each required for chromosome distribution at meiosis I. All four genes are transcriptionally induced during meiosis. The experimental approaches include: 1) in vitro mutagenesis of the regulatory regions to define cis-acting sequences responsible for meiosis-specific regulation, 2) mutant isolations to identify trans-acting factors that interact with these regions, 3) fusions to other yeast promoter-regulatory regions to determine how both time and level of expression affect meiotic and mitotic function, 4) purification of the proteins and the production of antibodies to study the properties and functions of the gene products and 5) searches for homologous genes in other eucaryotes to determine if these homologous genes have functions and regulation similar to the yeast genes.
