Oxygen toxicity in a fission yeast

✍ Scribed by Gerald L. Vaughan

• Publisher: John Wiley and Sons
• Year: 1971
• Tongue: English
• Weight: 676 KB
• Volume: 77
• Category: Article
• ISSN: 0021-9541
• DOI: 10.1002/jcp.1040770310

✦ Synopsis

Continuous exposure of synchronous cultures of Schizosaccharomyces pombe to 2.0 atmospheres oxygen beginning at any point in the first twothirds of the cell cycle prevented subsequent cell division. Similar exposure during the last one-third of the cell cycle did not prevent cell division. The inhibition of division was totally reversible. Exposure to 2.0 atmospheres oxygen for 2.5 hours did not affect oxygen consumption. Oxygen at 1.0 atmospheres reduced growth rate and protein synthesis by 44%. Similar exposure to 1.0 atmospheres reduced transport of glycine-14C, L-le~cine-~~C, and uracil-14C by 95 % , 73%, and 89% respectively. Analysis of the kinetics of uptake of these materials showed noncompetitive inhibition of transport by oxygen. The primary effect in rapidly appearing oxygen toxicity apparently involved interference with the transport capabilities of the cell membrane.