TABLE 2

Rate of His+ prototroph formation in various rad strains

Strain (rad mutation)Rate (× 10−8)aGAL1-his3-AI (% chromosomal)Rate (× 10−8)bGAL1-his3-ΔATG
YLD125 (RAD)6.5 (33)0.2
YLD157 (rad52)6.7 (87)0 (0/3.4 × 109)
YLD855 (rad51)31.6 (79)1.2
YLD658 (rad55)17.9 (66)1.1
YLD659 (rad57)19.0 (68)0.9
YLD655 (rad1)1.1 (33)0.01 (2/1.3 × 1010)
YLD746 (rad1rad52)6.1b (63)0 (0/3.7 × 109)
  • a Rates were computed by the method of the median Lea and Coulson (1949).

  • b Rates were computed by the Poisson distribution as the fraction of the tubes with no mutants.