Delta1 family members are involved in filopodial actin formation and neuronal cell migration independent of Notch signaling

► Delta1 induces actin-rich filopodial protrusions. ► A membrane-proximal domain of Delta1 is required for the protrusive activity. ► Delta1 regulates actin reorganization independently of Notch signaling. ► Delta is involved in neuronal cell migration independent of Notch activation.