Figure 2

Cell survival in SpRunt-1 morphant embryos is rescued by either injection of full-length SpRunt-1 mRNA, treatment with a caspase-3 inhibitor or injection of exogenous SpPKC1 mRNA. (A) DIC image of 48 h SpRunt-1 morphant embryo. (B) Confocal section of 48 h SpRunt-1 morphant embryo labeled with DAPI (blue) and TUNEL (green). (C) Confocal section of 48 h SpRunt-1 morphant embryo that was coinjected with full-length SpRunt-1 mRNA and then labeled with DAPI and TUNEL as in (B). All of the imaged embryos (6/6) from this group had the TUNEL-negative phenotype shown, and 12/12 imaged embryos in a separate rescue experiment were similarly TUNEL-negative. (D) DIC image of 48 h SpRunt-1 morphant embryo, from same set of injected embryos as that shown in (A) but treated with the caspase-3 inhibitor Ac-DEVD-CHO. (E) Confocal section of 48 h SpRunt-1 morphant embryo treated with Ac-DEVD-CHO and then labeled with DAPI and TUNEL as in (B). In a separate experiment, the frequency of imaged Ac-DEVD-CHO-treated morphants displaying a TUNEL-negative phenotype similar to that shown here was 11/21, similar to the frequency of morphants displaying rescued gastrulation (Table 1). (F) DIC image of 48 h embryo injected with SpRunt-1 MASO + SpPKC1 mRNA. (G) Confocal section of 48 h embryo injected with SpRunt-1 MASO + SpPKC1 mRNA and then labeled with DAPI and TUNEL as in (B). Arrows point to invaginated guts, which are outlined in (C), (E) and (G).