DELETIONS OF THE ISO-1-CYTOCHROME c AND ADJACENT GENES OF YEAST: DISCOVERY OF THE OSM1 GENE CONTROLLING OSMOTIC SENSITIVITY

Arjun Singh ¹ and Fred Sherman ²

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

Some of the deletions in the yeast Saccharomyces cerevisiae that encompass the CYC1 gene, which determines iso-1-cytochrome c, extend into the OSM1 gene, causing inhibition of growth on hypertonic media, and into the RAD7 gene, causing sensitivity to UV light. Two deletions (cyc1–363 and cyc1–367) encompass only the CYC1 gene, two deletions (cyc1–366 and cyc1–368) encompass the CYC1 and OSM1 genes, three deletions (cyc1–1, cyc1–364 and cyc1–365) encompass the CYC1, OSM1 and RAD7 genes, while none of the deletions extend into the closely linked SUP4 gene.