Table 1 . Frequency of reduction events.

				Reduction typee
Constructa	Source of DSBb	White-loss frequencyc	Reduction frequencyd	1	2	3
pWalkman{nbs-Ilp}
IS1	I-SceI	10% (24/230)	29% (6/21)	5	1	0
	P transposase	13% (19/150)	37% (7/19)	6	1	0
	Spontaneousf
	Female	0.1% (39/35,000)	37/37	1	35	1
	Femaleg	0.1% (22/15,000)	8/8	1	7	0
	Male	0.0% (0/8000)	0
IS2	I-SceI	13% (45/350)	39% (13/33)	6	1	6
	Spontaneousf female	0.1% (11/13,000)	11/11	0	11	0

^aConstructs used for site-specific integration.

^bThe source of DSB that led to the reported reductions.

^cFor induced events, the frequency was calculated by dividing the number of male parents yielding white-eyed progeny over the total number of males tested. The actual counts are included in parentheses. For spontaneous events, the frequency was calculated by dividing the number of white-eyed offspring over the total number of progeny. The counts are included in parentheses.

^dCalculated by dividing the number of confirmed reductions over all white-loss events tested by molecular means.

^eFor the molecular structure of different types of reduction events, see Figure 2.

^fSpontaneous events are categorized according to the gender of the duplication-carrying parents.

^gFlanking recessive markers were used to demonstrate homolog exchanges (see text).