Fig. 1. Diversity of Dp expression in human palm keratinocytes both in vivo and in vitro. (A) Confocal microscopic image of human palm skin labelled for Dp (green) and Dsgs (red). Both proteins show a low level of expression at the tips of the epidermal ridge (arrow head) but abundant immunoreactivity at the side of the ridge or above the dermal papillae (arrows), as well as in the suprabasal layers. (B) In situ hybridisation showing Dp mRNA expression in palm skin, and (C) the negative control with the randomer. Note clusters of small rounded cells located at the tips of the palm ridge express little or low level of Dp mRNA compared with the suprabasal cells. (D) Immunofluorescent staining for Dp in cultured palm keratinocytes. Diversity of Dp expression is seen and a few small rounded cells show a very low level of Dp expression, which is largely restricted to the cell boundary (arrow). Larger cells show Dp staining throughout the cells. (E) In situ hybridisation showing Dp mRNA expression in cultured palm keratinocytes. Note heterogeneous expression of Dp mRNA in vitro and little or no expression in clusters of small cells (arrows). Scale bar: (A-D) 20 µm, (E) 50 µm.