A genetic interaction between orc-ts alleles and mutations in the B-type histone acetyltransferase. (A) Analysis of tetrads from a cross of orc5-1 (JRY4250) with hat1Δ (BSY539) and hat2Δ (BSY540). Spores were incubated for 3 days at 31°C, which is the semi-permissive temperature for orc5-1. Double mutants are marked with circles. (B) Plating assay of orc5-1 hat1Δ (BSY538), orc5-1 hat2Δ (BSY602), and orc5-1 hat1Δhat2Δ (BSY603, BSY604) with control strains at indicated times and temperatures. Dilutions were 1:10, starting from late log-phase cultures on YPD. (C) Plating assays for orc2-1 mutant combinations with hat1Δ (BSY569) and hat2Δ (BSY572). (D) Plating assays as in B for orc1-161 mutant combinations with hat1Δ (BSY589-BSY591). (E) Growth comparison of orc5-1 hif1Δ (BSY595) with orc5-1 hat1Δ and orc5-1 hat2Δ at 30°C. For a detailed list of strains, see Additional file 7.