Table 3.
Offspring obtained from BrΔ/+ p21+/− × BrΔ/+ p21+/− crosses
| Ages
|
Total no.
|
BrΔ/+ p21−/−
|
Br+/+ p21−/−
|
BrΔ/Δ p21−/−
|
BrΔ/+ p21+/−
|
Br+/+ p21+/−
|
BrΔ/Δ p21+/−
|
BrΔ/+ p21+/+
|
Br+/+ p21+/+
|
BrΔ/Δ p21+/+
|
|---|---|---|---|---|---|---|---|---|---|---|
| E16 | 14 | 1 | 2 | 3 | 4 | 1 | 1 | 1 | 1 | 0 |
| E18 | 12 | 1 | 2 | 2 | 4 | 3 | 1 | 0 | 0 | |
| P1 | 71 | 13 | 7 | 6 + 1a | 20 | 9 | 1a | 8 | 6 | 0 |
| Predicted no. at P1b | 71 | 9 | 4.5 | 4.5 | 18 | 9 | 9 | 9 | 4.5 | 4.5 |
a
These two embryos (1 BrΔ/Δ p21−/−and 1 BrΔ/Δ p21+/−) were born dead. All six other BrΔ/Δ p21−/−embryos died within 24 h after birth. No live BrΔ/Δ p21+/−embryos found at birth suggests that loss of only one copy of p21 does not have an obvious effect on survival of BrΔ/Δ embryos.
b
Brca1 and p21 are located on mouse chromosomes 11 and 17, respectively. The predicted number is based on the Mendelien ratio.