Delta Like Protein 3 (dLL3)

DLL3 encodes a member of the delta protein ligand family. This family functions as Notch ligands that are characterized by a DSL domain, EGF repeats, and a transmembrane domain. Mutations in this gene cause autosomal recessive spondylocostal dysostosis 1. Two transcript variants encoding distinct isoforms have been identified for this gene.

In humans, the fact that mutations in genes required for oscillation, such as DLL3, result in abnormal segmentation of the vertebral column suggests that the segmentation clock also acts during human embryonic development. Disruption of the Notch pathway occurs in Alagille syndrome , a disorder that has vertebral abnormalities, i.e., 'butterfly vertebrae,' as a feature in about two-thirds of patients.