Figure 1.

Histone mutations suppress phenotypes caused by spt6-F249K. Strain 8857-13-1 pTF237 (spt6-F249K lacking genomic histone genes) (see Table 1) was transformed with low-copy centromere plasmids carrying the LEU2 marker and one copy of each histone gene with either the wild-type (WT) sequence or the mutation shown. After selecting for loss of the WT histone genes on pTF237, the strains were tested for growth under various conditions. Black font indicates mutations isolated only in the screen for suppressors of the temperature sensitivity caused by spt6-F249K, green indicates mutations isolated in a previous screen using an spt16-11 strain (Mccullough et al. 2011) that were found to also suppress phenotypes caused by spt6-F249K, and blue indicates mutations isolated in both screens. The number of independent isolates with the same mutation from the spt6-F249K screen are indicated. Cultures were grown to saturation in rich medium, and then aliquots of 10-fold serial dilutions were placed on the plates indicated and incubated at the temperature shown for the time given in days. Growth on medium lacking lysine indicates the Spt⁻ phenotype in these strains with the lys2-128∂ allele. HU indicates addition of hydroxyurea to YPAD (rich medium) at 90 or 150 mM.