Fig. 2. Keratinocyte adhesion and time-lapse migration studies show that Sdc1-null keratinocytes adhere better and migrate poorly compared with wt keratinocytes, but only when migrating on matrix they produce themselves. (A) Cell adhesion studies were performed on equal numbers of wt and Sdc1-null keratinocytes, which were allowed to adhere on wells coated with fibronectin (FN), vitronectin (VN), laminin-111 (LN-111), collagen I (CN-I) and collagen IV (CN-IV). Note that the Sdc1-null keratinocytes are significantly more adherent than the wt keratinocytes to all ECM molecules tested. (B,C) Cell migration was assessed in time-lapse experiments in wt and Sdc1-null keratinocytes 5 days after initial plating. For details on the quantification, see Materials and Methods. Velocity measurements for wt and Sdc1-null keratinocytes are presented in B. ^*P<0.05. Typical tracks (red) of 15 keratinocytes are shown superimposed over final relief-contrast images of wt and Sdc1-null keratinocytes in C. Bar, 10 µm. (D) Velocities of wt and Sdc1-null keratinocytes were compared after replating onto FNCNI matrix and onto LN-332 as well as onto matrices deposited by each keratinocyte genotype. Data show that after replating, Sdc1-null keratinocytes migrated more slowly than wt keratinocytes but only when replated on the Sdc1-null keratinocyte matrix.