Figure 3.

Conditional hMR expression in the skin during gestation provokes perinatal mortality. A: Number of mice alive at postnatal day 10 according to their genotype: wild-type (WT), monotransgenic tTA or hMR (K5-tTA or tetO-hMR), and DT (K5-tTA/tetO-hMR) pups. A major deficiency of DT mice was observed at day 10, attesting for their earlier mortality. B: DT mice recovered at E18.5 (ie, 1 day before birth), at postnatal day 1 (D1), and at day 10 (D10); results are expressed as the percentage of DT mice among offspring. At E18.5, the number of DT mice was close to that expected, ie, 25% (according to Mendelian distribution), whereas DT mice were all dead at the end of day 1, indicating perinatal mortality of DT mice. Administration of DOX or the MR antagonist potassium canrenoate during gestation prevented the mortality of DT pups, as seen in surviving treated DT pups at day 10. Numbers above bars indicate the number of DT versus total mice in each series. *P < 0.05; ***P < 0.001; χ² test.