Figure 1. Confocal images using actin (red) and nuclei (DAPI, cyan) staining of eyelids at different time points of meibomian gland morphogenesis. At E18.5 (A), we observed the formation of an epithelial condensation (asterisk) within the fused lid margin. Epithelial placodes in the superior and inferior lids also appeared opposite to each other, and were associated with condensation of mesenchyme as detected by cell alignment and increased actin staining of mesenchyme directly adjacent to the placode (arrows). At P0 (B), we observed an epidermal invagination (arrow) that undergoes proliferation and maturation with progressive enlargement and elongation adopting a tubular shape at P1 and P3 (C and D, respectively).