if o6-ethylguanine is an important lesion for producing specific-locus mutations , then its formation in the stem cells must be at least 4-fold greater than that for the whole testis as the enu exposure goes from 10 to 100 mg/kg : alternatively , the rate of repair of this lesion by the stem cells must decrease at least 4-fold relative to the average testicular cell .
C1708726
locus
C0007634
cell