Silencing by rpd3Δ was independent of known Rpd3 histone H4 targets. Endogenous copies of H3 and H4 were deleted and wild-type or mutant H3 and H4 were expressed from a CEN-ARS plasmid. Complete genotypes for all strains tested are in Table S1 (JRY9605, JRY9607–JRY9613, and JRY10644–JRY10655). Silencing was tested by mating to a MATa tester strain (JRY2726) and replica plated to minimal media. Growth indicates successful mating, which reflected extent of silencing.