Table 1.

Meiotic division and meiotic recombination in the xrs2 mutants

			Fold increase of recombinant fraction
Mutants	Spore formation	Spore viability	(24 h/0 h in SPM)
	(%)	(%)	Arg+	His+
No tag	86	97	600	340
Empty	36	0	1.8	1.6
ΔC 0	88	99	1600	330
ΔC 1	87	100	620	260
ΔC 2	87	92	1300	270
ΔC 3	85	86	840	190
ΔC 4	47	0	2.2	1.1
ΔN 0	73	76	290	51
ΔN 1	18	3	30	22
ΔN 2	31	0	24	5.8
ΔN 3	60	21	140	25.1
ΔN 4	87	86	930	130
ΔN 8	84	88	1900	290
ΔN 11	80	96	470	150
ΔN 12	66	18	140	51
ΔN 13	82	8	110	53
ΔN 14	78	38	110	77
ΔN 15	74	54	160	57
ΔN 16	87	40	550	110
ΔN 17	82	78	100	80
ΔN 18	77	96	650	180
ΔN 20	69	0	9.4	2.4
ΔN 21	35	0	1.3	1.1
K641E	46	0	1.7	1.7
4AQ	81	100	1300	240
ΔM	45	0	2.2	1.3
E-empty	46	0	2.9	1.3
E 1	56	3	5.0	6.9
E 4	67	39	76	19
E 1-K641E	53	0	3.6	0.8
E 4-K641E	31	0	4.6	2.3

Spore formation indicates percentage of cells containing more than one spore in all visible cells after 24 h. Spore viability was measured by dissection of asci by micromanipulation, and the proportion of spores germinating to give visible colonies was assessed. Eighteen asci were dissected for each strain.