Notch gain of function increases proliferation and is accompanied by an expansion of distal blastema marker expression into proximal regions. (A-C) BrdU-stained fin sections after a 10-hour heat-shock series (62-72 hpa) and quantification of the percentage of BrdU-labelled DAPI nuclei in the blastema: more cells incorporate BrdU in Tg(UAS:NICD) fins (B) than in wild-type fins (A). Asterisk in B indicates autofluorescent blood vessels. *P<0.05. (D-I) msxb, msxe and aldh1a2 in situ hybridization (5 dpa). Arrowheads indicate expression of msxb, msxe and aldh1a2. (J) qPCR analysis after a 10-hour heat-shock series (62-72 hpa): msxb, msxe and aldh1a2 transcripts are increased in Tg(UAS:NICD) fins. *P<0.05. Scale bars: 10 μm in B,I.