Figure 4. Colocalization studies reveal a complex spatial relationship between Cx47, Cx37, and Cx43 expression in the venous valve.
(A) A saphenous vein valve (arrow) longitudinal section immunolabeled for Cx37. The section was a glancing one at the point where the valve leaflet starts to merge with the wall of the vein. (B) The same valve section as in A immunostained for Cx47. (C) An overlay of the Cx37 and Cx47 staining shown in A and B. A highly localized area of the valve showing intense, line-like Cx47 immunosignal is shown at higher magnification in D. Note that in this example, there was little or no overlap between the Cx37 and Cx47 signals. (E) A different saphenous vein valve (arrow) immunostained for Cx37. (F) The same valve section as in E immunolabeled for Cx47. (G) Overlay of the Cx37 and Cx47 staining shown in E and F. An area of the valve showing intense, line-like Cx47 staining is shown at higher magnification in H. In this case, there was significant overlap between the Cx37 and Cx47 signals. (I) A high magnification view of another saphenous vein valve (en face orientation) immunostained for Cx47. (J) The same valve section as in I immunostained for Cx43. (K) The overlay of I and J shows that the weaker punctate Cx47 signal colocalizes with Cx43. (L) A high magnification view of a different saphenous vein valve (en face orientation) immunolabeled for Cx47. (M) The same valve section as in L immunostained for Cx43. (N) Overlay of Cx47 and Cx43 staining shown in L and M. Note that the weaker, punctate Cx47 signal in the valve colocalizes with Cx43 but the intense, line-like Cx47 signal is distinct from the Cx43 signal. Blood flow is from left to right in A–H. Scale bars: (A–C) 20 µm; (D) 20 µm; (E–G) 20 µm; (H) 10 µm; (I–K) 10 µm; (L–N) 10 µm