TABLE 1.
Timing of lethality in progeny arising from Rb+/− × K-ras+/− crossesa
| Stage | No. of live (nonviable) embryos recoveredb
|
|||||
|---|---|---|---|---|---|---|
| Rb+/+ K-ras+/+ | Rb+/+ K-ras+/− | Rb+/+ K-ras−/− | Rb−/− K-ras+/+ | Rb−/− K-ras+/− | Rb−/− K-ras−/− | |
| E9.5 | 2 | 6 | 2 | 3 | 5 | 3 (8) |
| E10.5 | 3 | 7 | 3 (1) | 3 | 6 | (3) |
| E11.5 | 6 | 12 | 5 (2) | 5 | 8 | (2) |
| E12.5 | 4 | 11 | 4 (1) | 5 (3) | 11 | (4) |
| E13.5 | 7 | 13 | 4 (3) | 4 (4) | 12 (1) | (5) |
| E14.5 | 9 | 17 | 4 (5) | 3 (7) | 15 (3) | ND |
| E15.5 | 6 | 10 | 2 (4) | (5) | 7 (4) | ND |
| E16.5 | 7 | 10 | 1 (5) | (6) | (10) | ND |
a
Embryos with the indicated genotypes were recovered at different embryonic stages and assessed for viability (beating heart).
b
ND, no data (no embryos were recovered).