Table 4.
Genotypic frequency distribution of transgenic mice obtained from tetO-MoPrP × tTA crosses
| Crosses
|
Treatment* | No. born | No. neonatal deaths | Deaths, %† | No. screened | Genotypes, %
|
||||
|---|---|---|---|---|---|---|---|---|---|---|
| tTA | PrP | TetO-MoPrP | tTA | Non-Tg | tTA:PrP | |||||
| F959 | E6740 | − Dox | 460 | 92 | 20.0 | 368 | 30.7 | 32.3 | 29.3 | 7.6 |
| + Dox | 187 | 14 | 7.5 | 175 | 22.9 | 25.1 | 28.0 | 24.0 | ||
| + Dox E13 or E14‡ | 24 | 4 | 16.7 | 20 | 30.0 | 25.0 | 25.0 | 20.0 | ||
| + Dox E17 or E18‡ | 45 | 3 | 6.7 | 42 | 21.0 | 31.0 | 43.0 | 5.0 | ||
| + Dox P2, P4, or P6§ | 39 | 8 | 20.5 | 31 | 21.0 | 31.0 | 43.0 | 0.0 | ||
| F966 | E6740 | − Dox | 188 | 22 | 11.7 | 166 | 42.2 | 23.5 | 24.1 | 10.2 |
| + Dox | 216 | 8 | 3.7 | 208 | 29.8 | 24.5 | 24.5 | 21.2 | ||
*
Treatment refers to 2 mg/ml of doxycycline administered orally; − Dox, no treatment; + Dox, doxycyline during embryonic and postnatal development.
†
Neonatal deaths were observed during the first 3 postnatal weeks.
‡
E refers to the embryonic days at which doxycycline treatment was initiated.
§
P refers to the postnatal days at which treatments were initiated.