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Fig. 6
Minimal apoptotic cell death is observed in the optic fissure, but is increased in the MHB and POM in pax2a and pax2a; pax2b mutants. Whole‐mount immunofluorescence for cell death (green; activated Caspase‐3) and nuclei (magenta; TO‐PRO‐3) at 24 hpf (A‐D), 36 hpf (E‐H), and 48 hpf (I‐L). All images are lateral views of three‐dimensional renderings. (A) Wild‐type, (B) pax2a tu29a , (C) pax2b sa10953 , (D) and pax2a tu29a ; pax2b sa10953 embryos at 24 hpf. (E) Wild‐type, (F) pax2a tu29a , (G) pax2b sa10953 , (H) and pax2a tu29a ; pax2b sa10953 embryos at 36 hpf. (I) Wild‐type, (J) pax2a tu29a , (K) pax2b sa10953 , (L) and pax2a tu29a ; pax2b sa10953 embryos at 48 hpf. White arrowheads, examples of cells labeled with activated Caspase‐3 elsewhere in the optic cup, brain, or POM. (M‐O) Quantification of total number of activated Caspase‐3‐positive cells throughout the depth of the optic fissure within the optic cup, at 24 hpf (M); 36 hpf (N); and 48 hpf (O). n (embryos) shown at base of graphs. P‐values for (M‐O) were calculated using an unpaired Student's t‐test. Schematic (M) shows the specific region of the optic fissure through the optic cup in which activated Caspase‐3‐positive cells were quantified. (P) Table summarizing number of embryos at 24 hpf containing five or more activated Caspase‐3‐positive cells located in the forebrain, MHB, and POM for each genotype. mhb, midbrain‐hindbrain boundary; pom, periocular mesenchyme; fb, forebrain