TABLE 2.

HTAX-neo3 somatic replacing HTAX S134A mutant could not rescue its phenotype during conjugationa

MatingPercentage of exconjugants by conjugation typePmr/Cyr (%)
6-h pairing10-h pairing10-h anlagen10-h exconjugants29.5-h exconjugants
CU427 × CU42881.570.0100.015.468.40
CU427 × S134A52.023.03.006.716
CU427 × rejuvenated S134A (50-3)23.218.29.505.916
CU427 × rejuvenated S134A (62-5)48.610.65.902.510.4
  • a To determine whether the S134A mutation only causes the meiosis defect, the mutant HTAX S134A gene was replaced with the WT HTAX-neo3 gene in MACs of the S134A rescued cells (Fig. 5A). These cells now contain WT HTAX genes in MACs but retain MICs that could have kept any DSBs accumulated earlier. Two such strains were made (50-3 and 62-5). The conjugation results showed that the strains that replaced the S134A mutation in MACs of S134A rescued cells did not reduce the meiotic defects, as indicated by the low percentage of exconjugants and low Pmr/Cyr ratio. Experiments were repeated twice with similar results.