Figure 6.

Mature GATA-3-null hair follicles exhibit biochemical signs of an expanded cortex and medulla and a severely reduced inner root sheath. (A–J) Matched P35 skin grafts from E17.5 GATA-3-null (KO) and wild-type littermates were frozen and sectioned (10 μm) and subjected to triple indirect immunofluorescence microscopy. Most follicles were in the anagen phase of the hair cycle. The upper right denotes genotype of skin. The antibodies used are noted on each frame and are color-coded according to the secondary Ab used for detection. DAPI was used to mark the nuclei, AE13 for cortical keratins, AE15 for IRS and medulla trichoyalin, anti-K6 for the companion layer and medulla (this antibody does not detect the IRS-K6 keratins), and Lef-1 to mark the precortical cells. denotes the wide stripe of AE13-negative, AE15-positive cells, corresponding to the medulla at the hair shaft center. Note the expanded Lef-1-positive precortex and AE13-positive cortex in mutant follicles. Brackets denote the AE15-positive IRS, largely absent in the KO follicles. Arrows indicate the lowest extent of AE15-positive IRS staining.