FIG. 1.

(A) Lack of complementation for MMS sensitivity between the rad58-4 mutant and the mre11 disruptant. Diploids obtained by mating rad58-4 (20B-D3142) with an mre11 (HTY231) (solid circles) strain and with a wild-type strain (CG379) (open circles) were grown in yeast-peptone-dextrose (YPD) liquid medium, diluted appropriately, and spread on YPD plates containing various concentrations of MMS, and the plates were incubated at 30°C for 3 days. Colonies growing on each plate were counted. (B) Complementation of the repair defect of the rad58-4 mutant with the cloned MRE11 gene. The rad58-4 mutant (HTY553) carrying the MRE11 gene on a single-copy vector, pHT62 (open circles), or the vector alone, YCp50 (solid circles), was tested for MMS sensitivity. Each transformant was grown in SD-URA, diluted appropriately, and spread on SD-URA plates containing various concentrations of MMS.