Figure 6.
Some activation-defective cellular mutants fail to spread. Equal numbers of cells were plated out on tissue culture plastic in complete medium. After incubation overnight at 37°C, the cells were viewed and photographed using a Nikon Diaphot inverted phase microscope. (A) The parental cell line, expressing αIIbα6Aβ3β1, spread normally on serum-coated tissue culture plastic. The cells had a similar appearance when plated on fibrinogen or fibronectin (data not shown). (B) In contrast, nine of these cell lines failed to spread on any of these substrates. Depicted is the appearance of a representative cell line, plated on tissue culture plastic. (Bars = 20 μm.)