This award will support collaborative research in eukaryotic genetics between Dr. James Haber, Brandeis University, and Dr. Bernard Dujon, Pasteur Institute, Paris, France. The objective of the project is to compare and contrast two different recombination systems of yeast. The role of double-strand breaks (DSB) in initiating recombination has been well established in experiments ranging from X-ray induction of recombination to the "targeted" transformation of restriction endonuclease-cleaved DNA. In this project, the researchers will compare and contrast HO- and w-endonuclease initiated DSB recombination in yeast, using genetic and physical methods of analysis. The work will be carried out using galactose- or phosphate-regulated genes to control expression of the nuclease. Recombination will be primarily assayed using a plasmid containing transcribed and untranscribed copies of the E.coli LACZ gene, where the transcribed copy is disrupted by the endonuclease recognition sequence. Both researchers have carried out significant work on recombination systems, and the proposed project will benefit greatly from their combined expertise. This collaboration offers a unique approach to the study of recombination events that occur in different organelles of the eukaryotic cell.
