Death resulting from fatty acid starvation in yeast

Mutants of Saccharomyces cerevisiae having the genotypes fas1 (fatty acid synthetase minus) and fas1, ole1 (fatty acid synthetase and fatty acid desaturase minus) were found to undergo logarithmic death when deprived of required fatty acids, whereas ole1 strains did not. During the first 2 to 3 h of fatty acid starvation, macromolecular synthesis occurred at apparently normal rates, although cell division stopped by the end of the 1st h. Cell death commenced at approximately the 2nd to the 3rd h, and within 24 h, depending upon conditions, 2 to 4 log orders of death had occurred. The loss of viability was accelerated by the addition of detergent, but could be largely prevented by the interruption of protein synthesis, either by amino acid starvation or by the use of cycloheximide. The possible significance of this phenomenon in terms of membrane biosynthesis is discussed.