C) NPL3 over expression stabilizes telomeric R-loops. The indicated strains were grown on 1% raffinose 2% galactose to induce NPL3 over expression. Cross-linked samples were subjected to DRIP. DNA-RNA hybrids were immunoprecipitated using the S9.6 antibody. R-loop levels were determined by quantitative PCR on indicated telomeres. Data represents mean % input +/- SEM relative to 250 mM HU eV n=3 (paired t-test two tailed *p<0.05, **p<0.01). Abbreviations eV: empty vector control, oE: over expression HU: hydroxyurea. *p<0.05, **p<0.01 