FIGURE 6:

Rap1 RNAi leads to widespread disruption of epidermal integrity, more severe than that seen after Cno loss. (A–D) Stage 11. (A) The WT epidermis remains intact despite segmental cell shape change and tracheal pit invagination. Dorsal, lateral, and ventral epidermal regions are indicated. (B) In less severe Rap1 RNAi embryos, most of the ventral epidermis is lost and infolding cells are seen there (red arrows). The dorsal epidermis remains more intact (green arrows). (C) In more severe Rap1 RNAi embryos only small regions of intact dorsal epidermis remain near the amnioserosa (green arrows). The lateral and ventral epidermis are totally disrupted, with the apical ends of infolded cells seen in some places (red arrows). (D) In cnoM/Z null mutants the ventralmost epidermis is disrupted (bracket) and occasional infolding is seen (red arrow) but the region of remaining intact epidermis is more substantial (green arrows). (E) Later stage Rap1 RNAi embryo. Staging becomes difficult as only small regions of intact epidermis remain (green arrows). (F) In contrast, stage 13 cnoM/Z null mutants retain intact dorsal and lateral epidermis but do fail during dorsal closure and have the deep segmental groove phenotype.