This three-year award for U.S.-France cooperative research on genetic recombination involves Stephen Kowalczykowski of the University of California at Davis, Alain Nicolas, Marie Dutreix, and Francis Fabre of the Institut Curie in Paris, France. The award provides travel support and living expenses to Dr. Kowalczykowski and a graduate student. The objective of their research is to investigate homologous pairing and subsequent exchange of DNA strands. This process is mediated by a unique class of proteins represented by the prototypic RecA protein from Escherichia coli and by the new Rad51 protein from Saccharomyces cerevisiae. The U.S. investigator brings to this collaboration expertise in the physical and biochemical aspects of recombination. This is complemented by French expertise in molecular genetics. The project will advance fundamental understanding of the biological processes involved in genetic recombination, including aberrant processes that lead to deleterious genomic rearrangements.