Figure 4

Temporal and spatial expression profiles of sample genes from the activation and effector clusters. Temporal and spatial profiles of the (a-h) activation and (i-p) effector clusters. The line graphs display temporal expression: absolute expression levels (y-axis) at each time point (x-axis) with both PU.1 null (pink) and wild-type profiles (blue). The y-axis range varies depending on the expression levels for each gene. The photomicrographs show in situ hybridization on 3 h (b,d,f,h) and 12 or 24 h (j,l,n,p) frozen wild-type wounds. (a,c,e,g) Temporal profiles of each of the activation genes show a rapidly induced but transient expression peak at 3 h in both PU.1 null and wild-type wounds. (b) Krox24 is expressed by wound margin epidermal cells extending back 10-12 cell diameters from the wound edge and also by associated hair follicles (arrows). (d) MKP-1 is expressed by the first 5-8 front-row keratinocytes and a subset of dermal fibroblasts (arrows). (f) High levels of Fosl1 expression in wound margin epidermal cells and weaker expression in damaged hair follicles (arrows). (h) EST GenBank accession number AI853531 appears to be expressed by wound fibroblasts (arrows). (i,k,m,o) The early and late effector gene samples all exhibit expression profiles with upregulation either at 12 h (i,k), or 24 h (m,o), whether in PU.1 null or wild-type wound tissues. (j) Map4k4 is expressed up to 10-12 cell diameters from the wound edge and in dermal fibroblasts (arrows). (l) Rbp1 is expressed in epidermal cells approximately 15 cell diameters from the wound site. (n) K6 expression is restricted to 10-12 rows of wound edge keratinocytes. (p) MRP8 has a rather similar keratinocyte expression to K6, but is also expressed to a lesser extent in leukocytes in wild-type wounds (arrows). Scale bar = 400 μm.