Table 1.

Effect of combining the exonuclease and active site mutations in Pol ε gene on mutation rates in haploids in 8C-YUNI101 genetic background

POL2 allele	Mutation rates for different markers*
	Forward mutation	Reversion
		Base substitutions	Frameshifts (+1)
	Canr (× 10-7)	Ura+ × (10-8)	His+ × (10-8)
Mismatch repair proficient strains
wild-type	3.3	1.3	1.1
	2.5–4.9	1.1–1.7	0.9–3.5
pol2-Y831A	5.1	1.2	1.6
	3.5–12.1	0.8–2.8	0.5–2.7
pol2-4	27	3.41	452
	15–42	2.4–5.7	35–78
pol2-4,Y831A	9	1.5	3.93
	7–15	1.1–1.9	2.3–5.4
Mismatch repair deficient strains (pms1)
wild-type	90	2.8	87
	72–150	2.4–4.1	54–150
pol2-Y831A	340	124	4705
	230–420	11–19	270–790
pol2-4	760	1606	16007
	120–1060	90–420	950–2800
pol2-4,Y831A	270	158	4109
	190–440	8–55	260–440

*Here and thereafter, median for 9–27 independent cultures with 95% confidence limits below. ¹14/16 of revertants sequenced were due to C->A transversions ²20/20 revertants sequenced contained a +1A frameshift event ³16/16 revertants sequenced were due to +1A frameshift ⁴12/14 revertants were due to C->A change ⁵15/15 revertants sequenced were due to +1A frameshift ⁶12/12 revertants sequenced were due to C->A mutation ⁷16/16 revertants sequenced were due to +1A frameshift ⁸12/15 revertants sequenced were due to C->A mutation ⁹14/14 revertants were due to +1A frameshift