Table 1.

Progeny genotypes agree with Mendelian expectations

Maternal genotype:	COX-1(+/−)/COX-2(+/−)		COX-1(−/−)/COX-2(+/−)
Paternal genotype:	COX-1(−/−)/COX-2(+/−)		COX-1(−/−)/COX-2(+/−)
Offspring genotype	Expected ratio	Obtained ratio*	Expected ratio	Obtained ratio†
COX-1(+/−)/COX-2(+/+)	0.125	0.110	NA	NA
COX-1(+/−)/COX-2(+/−)	0.250	0.253	NA	NA
COX-1(+/−)/COX-2(−/−)	0.125	0.115	NA	NA
COX-1(−/−)/COX-2(+/+)	0.125	0.133	0.250	0.241
COX-1(−/−)/COX-2(+/−)	0.250	0.293	0.500	0.474
COX-1(−/−)/COX-2(−/−)	0.125	0.110	0.250	0.285

Litters were delivered after a normal gestation length of 19.5 days. Expected ratios are the Mendelian expectations. All obtained ratios are not significantly different from expected ratios (χ² statistic, P < 0.01). 

^*269 mice analyzed. 

^† 341 mice analyzed. NA, not applicable.