Salts, Y., Department of Biology, University of California, San Diego, La Jolla, 92093, California, United States
Simchen, G., Department of Genetics, The Hebrew University of Jerusalem, Jerusalem, Israel
Piñon, R., Department of Biology, University of California, San Diego, La Jolla, 92093, California, United States

Irradiation of meiotic yeast cells with moderate doses of ultraviolet irradiation (1,600 erg/mm2) leads to the arrest of premeiotic DNA synthesis, massive (5-40%) DNA degradation, and a 40-50% loss of cell viability. In contrast, such doses of UV irradiation had a minor effect on viability (15-20% loss) of logarithmically growing cells, and no comparable DNA degradation was observed in irradiated synchronized vegetative cells. Meiotic recombination is also affected by UV irradiation. When administered at a stage comparable to meiotic prophase, low doses of irradiation result in a reduction in recombination frequency without significantly affecting cell viability. © 1976 Springer-Verlag.