The role of Set1 in meiotic replication is independent of its HMTase activity but requires the presence of the SET domain. (A) Protein cell extracts from the indicated strains (DBY745 background) were subdivided and probed with dimethylated H3-K4 antiserum (top) or with C-term H3 antiserum (bottom). Strains carrying the deletion of the NHCC and SEEL motifs in the SET domain or the G951S substitution are denoted by set1ΔNHCC, set1ΔSEEL, and G951S, respectively. (B) Progression into meiotic DNA replication of WT, set1Δ, swd3Δ, set1ΔNHCC, and set1ΔSEEL was analyzed by FACS. (C) Progression into meiotic DNA replication of the G951S mutant. (D) The set1Δ diploid (SK1 background) was transformed by the vector pYX (pYX243), pYXSET900–1080, pYXSETΔNHCC, pYXSETΔSEEL, and pYXSETG951S directing the expression of the wild-type SET domain (900–1080) or of SET domains carrying the indicated mutations. Meiotic replication was analyzed by FACS analysis.