Isolation and characterization of temperature-sensitive mutants of Saccharomyces cerevisiae.
Temperature-sensitive (ts) mutants of Saccharomyces cerevisiae Y-196 were isolated by UV irradiation and/by EMS treatment. There were 163 ts mutants isolated from 66,957 colonies. These mutants were designated as AMY-1 to AMY-163. These ts mutants grew normally at 30 degrees C, but did not grow at 38 degrees C. In an auxanographic study, we showed that AMY-46 was an absolute ts mutant, while AMY-10, AMY-15, AMY-16, AMY-49, AMY-66, AMY-88, AMY-114, AMY-126, AMY-127, AMY-129, AMY-136, AMY-150, AMY-157, AMY-158, AMY-159, AMY-161, and AMY-162 were auxotrophic ts mutants except AMY-16 had cell size 2-42% larger than that of the wild type. Cell aggregation phenomenon was found when the ts mutants were cultivated at 30 degrees C to stationary phase then cultured at 38 degrees C for 4 hr. The budding numbers at 30 degrees C were less than that at 38 degrees C. Mutant AMY-49 had the highest budding number. There was a positive correlation between the growth rate and the average budding number. However, there was a negative correlation between the growth rate at 30 degrees C and the length of long axis of cell or the size of cell.
Yang
S S
SS
Department of Agricultural Chemistry, National Taiwan University, Taipei, R.O.C.
Sung
T F
TF
Wei
Y L
YL
D009154:Mutation; D012441:Saccharomyces cerevisiae / Q000254:growth & development / Q000302:isolation & purification*; D013696:Temperature