Fig. 4. Expression of classical cadherins in the forelimb bud of mouse. (A-C) Double immunostaining of a longitudinal section of the forelimb bud at E9.5 shows that the expression of E-cadherin (green, A) and P-cadherin (red, B) overlaps along the AER (yellow in merged image, C). (D,E) Transverse section of the forelimb bud at E10.5 shows the strong expression of E-cadherin throughout the AER. (F-H) N-cadherin is strongly expressed at mesenchyme just beneath the AER (F), whereas E-cadherin is prominently expressed in the AER (G). The merged image of F and G clearly demonstrates their distinct expression patterns (H). Counterstaining with DAPI is shown in blue in C and in red in D,E. Scale bars: 100 µm in A-D,F-H; 20 µm in E.