Different radio-sensitivity of <i>C</i>. <i>neoformans</i> H99S vs H99 strains and their DNA damage progression after 1 kGy exposure.

(A) H99S and H99 cells were cultured in YPD overnight, and then 10-fold serially diluted (102 to 105) in PBS and 3 μL of diluted solution was spotted onto the YPD plates. Cells were exposed to the indicated doses of γ-radiation and then further incubated at 30°C for 5 days. Image was from one representative experiment of three independent experiments. (B) & (C) DNA damage progression of C. neoformans H99S and H99 cells after 1 kGy γ-radiation measured by mitochondrial DNA and nuclear DNA LR-QPCR, respectively. After radiation, cells were harvested at selected time points and DNA was extracted and PCR was performed using 1 ng DNA and 30 ng DNA for the long mitochondrial DNA fragment and long nuclear DNA fragment respectively. Results were from three independent experiments with triplicate samples in each experiment (3 samples/point/experiment x 3). Mean ± S.E.M. **, p<0.01; ***, p<0.001.