FINE STRUCTURE MAPPING IN YEAST WITH SUNLAMP RADIATION

Christopher W. Lawrence ¹ and Roshan Christensen ²

¹ Department of Radiation Biology, University of Rochester, Rochester, New York 14642
² Department of Biophysics, University of Rochester, Rochester, New York 14642

The X-ray mapping procedure of Manney and Mortimer (1964) is the most widely applicable and convenient method for fine structure analysis in yeast, but suffers the disadvantage that suitable X-ray machines or gamma ray sources are very expensive. Although many other recombinogens are known, none gives a linear dose-response like X-rays and few are as convenient or give as reproducible results. Experiments with Saccharomyces cerevisiae reported in this paper show, however, that the near-ultraviolet radiation emitted by fluorescent sunlamps gives linear dose-response relations, as reproducible results as ionizing radiations, and map distances which correlate highly with those obtained by using ⁶⁰Co gamma rays. It is suggested that this convenient recombinogen may be a suitable low-cost substitute for ionizing radiations in fine structure mapping.