Abstract
Genetic studies of meiotic recombination in Saccharomyces cerevisiae have provided a significant fraction of what we understand about the mechanism of recombination (Fogel et al. 1979; Esposito and Klapholz 1981; Szostak et al. 1983). A detailed genetic investigation of gene conversion events and associated reciprocal exchange of flanking markers has provided a wealth of information indicating that such events are not uniformly distributed along the chromosome. These findings have led to the publication of several detailed molecular models of recombination, most notably the single-strand initiation model of Meselson and Radding (1975) and the double-strand-break model of Szostak et al. (1981). The recent development of recombinant DNA techniques to clone, modify, and replace genes in yeast has now made it possible to begin an investigation of meiotic recombination at the molecular level. In this paper we concern ourselves with three fundamental questions: (1) Are there sequences that act as specific stimulators...