Fig. 3. Morphology, substrate adhesion and motility of BSp73AS-ß4 cells. (A) BSp73AS and BSp73AS-ß4 cells were grown on plastic culture dishes and were stained with Phalloidin-TRITC. As compared to the epitheloid BSp3AS cells, BSp73AS-ß4 cells resembled spindle shaped fibroblasts. Scale bar: 1.7 µm. (B) BSp73AS, BSp73AS-ß4, BSp73ASML and Progessor cells were labeled with [³H]thymidine and were seeded in triplicates on plates coated with BSA, recombinant Ln5, Col IV or Fn. After 20 minutes or 2 hours incubation, plates were vigorously washed. Adherent cells were detached and harvested. Radioactivity was determined in a ß-counter. The percentage (±s.d.) of adherent cells is shown. A significant increase in adhesion to the substrates as compared to BSA is indicated by an asterisk. Similar results have been obtained in repeated experiments using 804G supernatant as a source of Ln5. (C) BSp73AS, BSp73AS-ß4 and Progessor cells were seeded on recombinant Ln5-coated Petri dishes, where the central area was protected by a cover slide. After reaching subconfluency, the cover slide was removed. Thereafter medium was changed with the fresh medium contained only 1% FCS and either a control antibody, or B5.5 (10 µg/ml). After 72 hours, cultures were washed, cells were fixed and stained with Hematoxylin-Eosin. Pictures were taken at the boundary from where cells started to migrate (proximal) as well as from the center of the area initially protected by a cover slide (distant). Scale bar: 0.5 µm.