(A–C) n = number of embryos (A) Number of lateral endodermal cells in wild-type and toddler mutant embryos during gastrulation. (B) Rate of endodermal cell division in wild-type and toddler mutant embryos. 40–60 cells were tracked per embryo and the percentage of those cells that divided is shown. Red bars are averages. (C) Percentage of embryos with a given number of TUNEL +cells on one side of the embryo. (D) Representative images of TUNEL staining at two time points in toddler mutants. (E) Live tracking of endoderm using sox17:GFP transgenic fish captures two endodermal cells undergoing cell death during gastrulation in toddler mutants (arrows). A cell that is about to divide is also present (asterisk).