Figure 4
From: Fibronectin localization and fibrillization are affected by the presence of serum in culture media
Localization of fibronectin in HDFs cultured in 10% FBS.
Top: In 10% FBS both “total” FN (imaged with the FN-15 antibody, A and B) and ED-A FN (imaged with the IST-9 antibody, C and D) showed a strong epifluorescence emission, but a weak TIRF one. F-actin (green) showed a stronger TIRF emission due to the localization of many stress fibres on the ventral surface of HDFs. Please note that FN appears to be present in a perinuclear region in the two epifluorescence pictures; although frequent, this localization was not observed in all samples. Bottom: contact mode AFM pictures of fixed HDF in PBS. The cell surfaces present ridges with heights at most of a couple of hundreds of nm, which correspond to the dorsal actin fibres (smaller for transverse arcs); a similar picture is presented in Supplementary Information, Figure S3 (see Section 2 in Supplementary Information, Additional Materials and Methods for experimental details). The picture in the right hand part shows the full contour of a peripheral part of an HDF body, as highlighted by the black line); in areas where actin fibres are not present, the thickness decreases to less than 50 nm, which explains the bleeding of the dorsal fluorescence on the ventral plane in Figure 5.
