The Notch signalling pathway mutants, after-eight (aei), beamter (bea), and deadly-seven (des) have previously been used to study somitogenesis and neurogenesis. Notch signalling has also been shown to have roles in vascular development. However, vascular development in each of these three Notch mutants has not been described, and so their potential usefulness for further understanding the role of Notch signalling in angiogenesis is unknown. Here we demonstrate each of the mutants also exhibit vascular defects in inter-somitic vessel (ISV) positioning and patterning. Ectopic filopodia were also observed on the ISVs of the mutants. Ectopic filopodia are not due to loss of dll4. Somite expression of known vascular guidance cues, efnb2, sema3a2, and plexinD1 are disrupted, suggesting that the ISV vascular phenotype is due to disruption of these cues.
- intersomitic vessels