Table 1.

Summary of recombination frequencies from tetrads and pooled gametes.

Hotspot	F1 Hybrid	Frequency of recombinant chromatids per gametea
		Crossovers (95% CI, %)b		Noncrossovers (95% CI, %)b
		Oocyte	Ovary	Oocyte	Ovary
Psmb9	B10 x R209	1.7% (0.54–4.4)	2.0%c (1.6–2.5)	1.5% (0.65–3.0)	0.77%c (0.54–1.1)
	B10.A x SGR	1.5% (0.60–3.3)	0.79%c (0.50–1.2)	0.6% (0.22–1.5)	1.0%c,d (0.75–1.4)
		Spermatocyte	Sperm	Spermatocyte	Sperm
A3	A/J x DBA/2J	0.04% (0.02–0.06)	0.02%e (0.01–0.07)	0.31% (0.26–0.37)	0.29%f (0.23–0.36)

^aTo calculate recombination events on a per meiosis basis from a per gamete frequency, the crossover frequency is multiplied by 2 and the noncrossover is multiplied by 4, given that crossovers modify 2 of 4 chromatids while noncrossovers modify 1 of 4 chromatids.

^bConfidence interval (CI) calculations here and in the text use the Wilson procedure with continuity correction.

^cCrossover and noncrossover frequency calculations are restricted to those samples used for noncrossover measurements, as shown in Supplementary Figure 1 and Supplementary Table 1, accounting for the small differences from that previously reported²³.

^dNoncrossover frequency is derived from the B10.A chromosome only, which represents >95% of events²³.

^eThe crossover frequency is lower than that previously determined¹⁸, largely attributable to results from one of the animals in the current study.

^fNoncrossover frequency is derived from the DBA/2J chromosome only, which represents >80% of events as in Supplementary Fig. 2.