Recombination is not required for replication slowing or S-phase DNA damage checkpoint signaling, but abrogation of recombination suppresses the defects of the rqh1Δ and sfr1Δ mutants. (A) rhp51Δ (yFS566), swi5Δ (yFS553), and swi1Δ (yFS356) replication kinetics were assayed as described in Figure 1. (B) Replication kinetics of sfr1Δ rhp51Δ (yFS578), sfr1Δ swi5Δ (yFS554), sfr1Δ swi1Δ (yFS622), rqh1Δ rhp51Δ (yFS569), rqh1Δ swi5Δ (yFS565), mus81Δ rhp51Δ (yFS579), and mus81Δ swi5Δ (yFS581) strains. (C) Cds1 kinase activity in wild-type (yFS162), rhp51Δ (yFS566), sfr1Δ (yFS550), swi5Δ (yFS553), sfr1Δ swi5Δ (yFS554), and rad3Δ (yFS260) strains was assayed as described in Figure 1.