Figure 2.

KtyI and KtyII ablation causes epidermal thickening, hyperproliferation, cytolysis, and distinct structural abnormalities of the granular and stratum layers. (A) Hematoxylin/eosin-stained skin sections of E15.5 and E18.5 mouse embryos. Note apparently normal epidermis at E15.5 but hyperthickening and cytolysis (asterisk) in KtyI^−/− and KtyII^−/−_K8 at E18.5. Large keratohyalin granules in KtyI^−/− and their absence in KtyII^−/−_K8 epidermis, which shows a compact stratum corneum. Bars, 20 µm. (See also different magnification of other pictures in Fig. S3 A). (B) Measurements showing distinct increase of epidermal thickness at E18.5 in KtyI^−/− and KtyII^−/−_K8. (C) Ki-67–based quantification of proliferation rates in basal (B) and suprabasal (Sb) cells of the epidermis of WT and KtyI^−/− and KtyII^−/−_K8 embryos at E18.5 (see pictures in Fig. S3 C), showing significant increase in the absence of KIF. ***, P ≤ 0.001.