Table 1.
Summary of chimeric mouse survival and LacZ expression
| Embryonic day | Uterine sacs (A) | Embryos (B) | B/A, % | LacZ positive (C) | C/B, % | No. of embryos per clone
|
||
|---|---|---|---|---|---|---|---|---|
| −/−Clone 1 | −/−Clone 16 | −/−Clone 64 | ||||||
| KZ26 (+/−) chimeric mice | ||||||||
| E9.5 | 30 | 30 | 100 | 15 | 50 | |||
| E10.5 | 18 | 18 | 100 | 13 | 72 | |||
| E11.5 | 15 | 15 | 100 | 11 | 73 | |||
| E12.5 | 15 | 15 | 100 | 10 | 67 | |||
| KZ26 (−/−) chimeric mice | ||||||||
| E9.5 | 12 | 12 | 100 | 10 | 83 | 10 | 2 | nd |
| E10.5 | 134 | 117 | 87 | 85 | 73 | 38 | 22 | 57 |
| E11.5 | 92 | 29 | 32 | 7 | 24 | 12 | 17 | nd |
| E12.5 | 71 | 22 | 31 | 5 | 23 | 16 | 0 | 6 |
| E14.5 | * | 20 | 8 | 40 | 13 | 7 | nd | |
Summary of chimeric mouse survival. Chimeric mice were produced from the injection into blastocysts of ES cells with a knock-in of lacZ into one allele of Lmo2 (KZ26 +/−) or a knock-in of lacZ into one allele of Lmo2 and a knock-out of the second allele by insertion of hygromycin (KZ26 −/−). These blastocysts were implanted into recipients. At the specified embryonic time points, uterine sacs were counted, and embryos were dissected and stained for β-galactosidase activity with X-Gal. The data are expressed as the percentage of live embryos per total uterine sacs (A/B) (those embryos with marked degeneration were not included) and the percentage of β-galactosidase-positive embryos (C/B). For the KZ26 −/− ES clones, the number of embryos examined for each clone is given (note that no clone 64 embryos were examined at E9.5, E11.5, or E14.5).
*Uterine sacs uncountable because of degeneration.