Table 1.

Mutation rates at URA3. Mutation rates were measured as described in (15). Parentheses contain the numbers of A–T to T–A plus T–A to A–T substitutions observed among the total number of ura3 mutants sequenced. CI, confidence interval.

Yeast strain	Location and origin	URA3 orient.	Mut. rate (× 10−8)	95% CI	A–T to T–A plus T–A to A–T (× 10−8)	Occurrences A–T to T–A: T–A to A–T
Wild type	R-ARS306	1	6.6	3.5–12	1.6 (3/12)	2:1
		2	5.9	1.6–17	1.5 (2/8)	1:1
pol2-M644G	L-ARS306	1	16	11–36	5.3 (7/21)	1:6
		2	45	23–60	29 (20/31)	18:2
	R-ARS306	1	28	13–40	19 (45/61)	43:2
		2	16	9.7–36	2.1 (5/38)	1:4
Wild type	R-ARS501	1	3.9	3.2–7.2	0.16 (1/24)	0:1
		2	3.1	2.2–6.4	0.25 (2/25)	1:1
pol2-M644G	R-ARS501	1	26	17–40	17 (22/34)	22:0
		2	21	15–44	5.9 (9/32)	2:7