Figure 6

Apoptosis in Birc5 -depleted embryos. Tg(Fli:eGFP) embryos reveal apoptosis (red) in relation to blood vessels (green) (A-O). A-I: Morphants at 1 dpf exhibit increased apoptosis, particularly in the brain (B) and along neural tube (E) in Birc5a morphants (morpholino dose 2 ng). Birc5b depletion with 4 ng of morpholino caused apoptosis in axial vessel region, caudal vein plexus, and neural structures (C, F). G-I: Confocal microscopy of 1 μm sagittal "slice" in region of caudal vein plexus and corresponding neural tube (excludes somites): Dose-dependent changes in apoptosis in caudal vein plexus region (J, region II) and corresponding neural tissue (J, region I) after Birc5 knockdowns was quantified at 1 dpf. High dose Birc5a morpholino (2 ng) or Birc5b morpholino (4 ng) causes significant increase in apoptosis in caudal vein plexus and neural tube (K, L). With lower Birc5a morpholino dose 0.5 ng), neural tube apoptosis remains significantly increased, but is almost absent in caudal vein plexus (N). Low dose Birc5b morpholino (1.0 ng) causes significant apoptosis in caudal vein plexus, but not in neural tube (O). Data presented in bottom panel. n = 30 × 3 independent experiments. * p < 0.05 relative to corresponding control. mhc: midbrain-hindbrain channel, aa: aortic arch, ax: axial vessels, cv: caudal vein plexus.