Figure 2.

Defects in ultrastructure of Fatp4^−/− corneocyte lipid envelope (CLE) and cornified envelope (CE). The CLE and CE were examined by transmission electron microscopy as described in Materials and Methods. The boxed regions in a to d are magnified in a’ to d’, respectively. White arrows indicate typical CLE morphology: a regular, 4 nm thick lucent band on the external face of the CE (black arrows). Fatp4^−/− stratum corneum (b’) was characterized by no visible CLE and a thin CE compared to control (a’), FATP4- (c’), and FATP1- (d’) rescued mice. Representative images are shown from two mice of each genotype. CE thickness was quantified (e) as described in Materials and Methods with the n numbers, standard deviation, and statistical significance indicated (***P < 0.001). IVL, involucrin promoter.