Table 1.

Genotypes of progeny from heterozygous integrin β8 intercrosses

	Integrin β8 genotype*
Age	+/+	+/−	−/−	Number of viable −/−†	Expected number of viable −/−	Expected −/− progeny (%)
E9.5	27 (31)	39 (45)	20 (24)	20	22	91
E10.5	48 (24)	101 (50)	52 (26)	41‡	50	82
E11.5	37 (32)	54 (46)	26 (22)§	12	30	40
E12.5	23 (25)	52 (57)	16 (18)	9	25	36
E13.5	25 (25)	65 (65)	10 (10)	10	30	33
E14.5	14 (45)	14 (45)	3(10)	3	9	33
E15.5	12 (36)	18 (55)	3 (9)	3	10	30
E16.5	11 (35)	17 (55)	3 (10)	3	9	33
P0–P4	58 (32)¶	103 (57)¶	20 (10)	20**	54	36

^*Numbers are given with percentages in brackets.

E, embryonic day; P, postnatal day.

Expected viable −/− calculated as if the sum of (+/+)+(+/−) is 75%.

^†Heart is beating.

^‡28 embryos had pale yolk sacs; 15 had dilated pericardiac cavities; 6 had no obvious vasculature; 5 had loose allantois-chorion connections.

^§Many embryos were deteriorating or being absorbed.

^¶Two +/+ and two +/− embryos had cleft palate and died. The rest were viable and fertile.

^**Two had a cleft palate. All had intracerebral hemorrhages.