Molecular Dissection of Mesenchymal–Epithelial Interactions in the Hair Follicle
Figure 5
Implementation of Array Analyses to Examine Characteristics and Dynamics of the Follicle DP Niche
(A) Semi-quantitative RT-PCR on mRNAs isolated from each population. Shown are representative data from molecular signature genes (see Figure 4) whose expression patterns in the DP niche environment had been previously uncharacterized. In this case, categories were consolidated into three groups: Signal transduction, transcription/nuclear, and cytoskeleton/ECM/cell adhesion. For each primer set, at least three different cycles were employed, and the resulting cDNA fragments were resolved by agarose gel electrophoresis along with DNA size markers to confirm that bands were of the expected sizes. For each gene, the data presented were from the cycle that provided the most meaningful comparisons. Note: bands seen in > 1 fraction accurately reflect mRNA expression at the differences in levels shown.
(B) Immunohistochemistry and in situ hybridizations. Skin sections were taken from 2-mo-old K14-GFPactin mice [49] whose follicles were at the transition from the resting to growing (telogen to anagen) stage of the hair cycle (8 wk) or from P4 WT mice (full anagen follicles) (all others). Sections were subjected to either immunofluorescence using color-coded Abs as indicated or in situ hybridization using the indicated biotinylated cRNA probes (sense controls were negative).