Death resulting from unbalanced growth in a temperature-sensitive mutant of Neurospora crassa.

A temperature-sensitive mutant of Neurospora crassa was found to undergo rapid death on minimal medium at 35 degrees C. The loss of viability in this mutant was prevented by various factors which retard growth, including deprivation of carbon sources or interruption of protein synthesis. Synthesis of nucleic acids and protein in this mutant was normal at the early stages of germination and then depressed at 35 degrees C. The active transport of glucose and the respiration rate in this mutant were depressed at 35 degrees C. Phopholipid synthesis was significantly repressed at 35 degrees C. The possible significance of the characteristics of this mutant is discussed in terms of membrane biosynthesis.