Table 1.
Outflow tract phenotypes in RA receptor mutant embryos.
| A. Tamoxifen treatment of CAGG-Cre,RARα1−/−, RXRαflox/flox embryos | ||||||||||
| Injection time |
Mutants | Litters | CAT | DORV | Overriding Aorta |
Normal | ||||
| E6.75–7.0 | 14 | 5 | 7 | 50% | 3 | 21% | 1 | 7% | 3 | 21% |
| E7.5–8.0 | 17 | 7 | 5 | 29% | 2 | 21% | 2 | 12% | 8 | 47% |
| E8.5 | 10 | 5 | 2 | 20% | 2 | 20% | 2 | 20% | 4 | 40% |
| E9.0–9.5 | 17 | 8 | 0 | 0% | 7 | 41% | 4 | 21% | 6 | 35% |
| E10.0–10.5 | 6 | 4 | 0 | 0% | 0 | 0% | 0 | 0% | 6 | 100% |
| B. Tissue specific inactivation in Cre,RARα1−/−, RXRαflox/flox embryos | ||||||||||
| Cre line | Mutants | Litters | CAT | DORV | Overriding Aorta |
Normal | ||||
| Mesp1Cre | 18 | 11 | 9 | 50% | 3 | 17% | 3 | 17% | 3 | 17% |
| Myf5Cre | 8 | 2 | 0 | 0% | 0 | 0% | 0 | 0% | 8 | 100% |
| Mef2cCre | 10 | 8 | 0 | 0% | 0 | 0% | 0 | 0% | 10 | 100% |
| Tie2Cre | 7 | 3 | 0 | 0% | 0 | 0% | 0 | 0% | 7 | 100% |
| C. Rescue of septation in RARα1/RARβ mutants by reduction of TGFβ2 gene dosage | ||||||||||
| Genotype | Mutants | Litters | CAT | DORV | Overriding Aorta |
Normal | ||||
|
RARα1−/− RARβ−/− |
* | * | * | 100% | 0 | 0% | 0 | 0% | 0 | 0% |
|
RARα1−/− RARβ−/− TGFβ2−/+ |
9 | 7 | 4 | 44% | 5 | 55% | 0 | 0% | 0 | 0% |
A. CAGG-Cre,RARα1−/−, RXRαflox/flox embryos were isolated following a single i.p. tamoxifen injection at the indicated times, and analyzed for cardiovascular defects. B. Phenotypes were scored in RARα1−/−, RXRαflox/flox embryos carrying the indicated Cre genes. C. Phenotypes were scored in double receptor mutant embryos with or without heterozygosity of Tgfb2.
*
The complete penetrance of CAT in RARα1/RARβ embryos is based on some embryos from the current study plus many from earlier analyses, totaling over 100 embryos in all.