Treatment with edelfosine induces expression of the SIR-dependent COS and PAU sub-telomeric gene families. (A) Growth of wild-type (W303) or sir4∆ cells expressing SIR4 from a centromeric plasmid or the empty vector (EV) on SD-Leu+Ade plates containing 20 μM edelfosine or vehicle. Plates were incubated at 30°C and imaged after 3 d of growth. (B) Growth of wild-type (W303) or endogenously tagged SIR4-GFP cells on synthetic solid medium containing 20 μM edelfosine or vehicle. Plates were incubated at 30°C and imaged after 2 d of growth. (C) Western blot of Sir4^MYC after 60 min with edelfosine or control. Bottom panel shows protein loading by TCE. (D and E) Sequence alignment of the highly similar COS (D) and PAU (E) family genes at the regions amplified by qPCR. Bold letters indicate binding sites for the general primers. (F and G) qPCR of the indicated genes in sir4Δ cells relative to wild type, expressed as ln(mutant/WT) (F) or in wild-type and sir4Δ cells treated for 60 min (G) with edelfosine or vehicle expressed as ln(EDLF/Ctrl). Bars represent mean ± SD for three independent experiments while circles represent individual experiments. * indicates P value <0.05 as determined by unpaired t tests with Holm-Šídák correction for multiple comparisons. For all panels: Ctrl = vehicle; EDLF = edelfosine. Source data are available for this figure: SourceData FS3.