Table 2.

MNase sensitivity (20 units) in meiosis (t = 4 h)

Mutant	Total DNA cleaved (hot spots), %		Ratio, mutant/wt		Ratio to premeiosis, hot spots
	Mutant	wt	Hot spots	Control sites	Mutant	wt	Mutant*
Type 1
mre2	16.8	31.1	0.6  ±  0.1	1.0  ±  0.3	1.0  ±  0.2	2.9  ±  0.6	1.0
mre11	17.7	21.5	0.8  ±  0.1	1.0  ±  0.1	1.4  ±  0.3	2.9  ±  0.5	1.4
Type 2
rad50Δ	14.9	10.9	1.3  ±  0.2	0.9  ±  0.1	2.2  ±  0.6	2.1  ±  0.5	3.0
xrs2	6.9	4.1	2.5  ±  1.9**	1.0  ±  0.1	2.3  ±  0.3	2.3  ±  0.5	2.9
rad50S	16.2	15.3	1.1  ±  0.1	1.1  ±  0.0	2.3  ±  0.6	2.2  ±  0.5	3.0
mre11-rad50Δ	12.9	17.7	0.7  ±  0.2	1.0  ±  0.0	1.2  ±  0.2	2.5  ±  0.9	1.4

Cells were sampled at t = 4 h. Data analysis and number of experiments are as shown in Table 1 and Figs. 1–3. Ratios of the sensitivity in mutants to wild type (wt) are calculated as in Table 1. Ratios of meiotic to premeiotic sensitivity are calculated by using premeiotic data in Table 1. Premeiotic to meiotic ratios for mutants* were calculated by the following formula: (premeiotic to meiotic ratio for mutants)/(premeiotic to meiotic ratio for wild-type) × 2.9, the premeiotic to meiotic ratio for wild-type in the mre2 experiment). The experimental variation in the xrs2 data (marked by the double asterisk) probably reflects subtle differences in procedures as performed by different experimenters. Data are the average ± SD.