FGFR2b-ligands signaling controls cell proliferation in the mesenchyme of the limb bud.

<p>(<b>A–D</b>) Phosphohistone H3 and E-cadherin double IF staining in control E11.5 (<b>A,B</b>) and DTG [<i>R26^rtTA/rtTA; Tg/Tg</i>] (<b>C,D</b>) limb bud exposed to Dox-IP at E10.5 and analyzed at E11.5 demonstrate significant reduction in cell proliferation of both the AER and the adjacent mesenchyme. (<b>E–H</b>) Caspase 3 IF staining for cell death in control limb bud at E11.5 (<b>E,F</b>) and DTG (<b>G,H</b>) limb buds exposed to Dox-IP at E10.5 and analyzed at E11.5 display significant decrease in apoptosis of the rudimentary AER, there is no change in the apoptosis of the adjacent mesenchyme. (Adj mesenchyme = Adjacent mesenchyme). (<b>I</b>) Quantification of PHH3 positive cells. (<b>J</b>) Quantification of caspase 3 positive cells. Bars represent the mean ± s.e.m. of at least 5 independent samples of each. Mann-whitney non-parametric test was performed. *p≤0.05. Scale bar A–H: 50 µm.