Synthetic lethality of asf1Δbdf1Δ
double-knockout strain in mitotic growth. The synthetic lethality of
asf1Δbdf1Δ is suppressed by a
single-copy plasmid, pRS-ASF1, which expresses the
ASF1 gene from its own promoter
(pRS-ASF1/asf1Δbdf1Δ,
−5-FOA). The viability of this strain without pRS-ASF1
was tested by the addition of 5-FOA into medium (+5-FOA). The
pRS316/bdf1Δ strain, the ASF1 gene of
which is coded on its chromosome, serves as a control to indicate that
the bdf1Δ strain itself is viable in the presence of
5-FOA.