Fig. 2.
Recombination is efficient by 36 hours following TM in Fgf8 temporal CKOs. (A-X) RNA in situ hybridization with the two Fgf8 probes indicated on adjacent medial or lateral sections of Fgf8 temporal CKO embryos treated with TM at the time-points indicated. The ages of the embryos analyzed are indicated under the arrows at the left. The control embryo is Fgf8flox/+; En2CreER/+ treated with TM at E8.5. The transcripts detected with the Fgf8 and exon 3 probes were greatly diminished in the dorsomedial isthmus (arrowheads). (K,L,O,P) Although the Fgf8 mutant transcript was detected in the dorsolateral isthmus of Fgf8-E9.5 CKO and Fgf8-E10.5 CKOs, the normal transcript was greatly diminished (arrows). (E-H, asterisks) The normal Fgf8 transcript was only partially reduced ventrally. (N,P,V,X, arrowheads) The normal Fgf8 transcript was greatly diminished by 36 hours after TM administration in the dorsal isthmus. Scale bars: in A, 500 μm for A-P; in Q, 500 μm for Q-X.