Fig. S1

epcam mutants form skin cell aggregates. (A) Confocal image (merged Z-stack) of basal keratinocytes of wild type control (WT) and maternal/zygotic epcam mutant (MZ-/-) embryos at 2 days post fertilization (dpf), after anti-p63 immunostaining of basal keratinocytes. Basal cell aggregates of mutant are indicated by red arrows. (B,C) Overviews (upper panels) and magnified views of tail region (lower panels) of live WT (left panels) and MZ-/- mutants (right panels) at 4 days post fertilization (dpf) (B) and 21 dpf, when the skin becomes multi-layered (C). The epidermal aggregates of mutants persist during further larval development (B; indicated by red arrows), whereas they are less prominent at 21 dpf (C). In addition, otoliths have recovered and acquired normal size at 21 dpf (C; indicated by black arrows). However, the skin of the mutant has a rougher morphology, the mutant is of reduced size (C; see different lengths of scale bars = 1 mm), and fin development is delayed, as judged by the less advanced fin ray formation in the developing unpaired anal, dorsal and tail fins (C; indicated by black arrowheads in wild-type animal). Further analyses have to reveal whether this is a skin/fin-specific defect, or a consequence of generally delayed development, growth and metamorphosis.