No, Norrin and Noggin are different genes with distinct functions and roles in development.

Key Differences between Norrin and Noggin:

1. Noggin:
   • Gene Symbol: NOG
   • Function: Noggin is a secreted protein that acts as an antagonist of BMP (Bone Morphogenetic Protein) signaling. It binds to BMPs and prevents them from interacting with their receptors, which helps to regulate dorsal-ventral patterning during early embryonic development.
   • Role in Development: Noggin is crucial for neural induction and dorsalization of mesoderm, particularly in the context of vertebrate development. It is one of the organizer molecules discovered in studies on Spemann’s organizer.
   • Pathways: It primarily modulates TGF-β family signaling, including BMPs.
2. Norrin:
   • Gene Symbol: NDP (stands for Norrie Disease Protein)
   • Function: Norrin is a secreted signaling molecule that functions as a ligand for the Frizzled-4 (FZD4) receptor in the Wnt/β-catenin signaling pathway.
   • Role in Development: Norrin is primarily involved in the development of the retina and inner ear. It plays a critical role in vascular development, especially in the retina and blood-brain barrier. Mutations in the NDP gene are associated with Norrie disease, which leads to blindness and other developmental issues.
   • Pathways: Norrin functions through the Wnt signaling pathway, specifically by binding to Frizzled-4 and LRP5/6 to activate β-catenin signaling.

Summary:

• Noggin is involved in BMP inhibition and dorsal-ventral patterning during embryonic development.
• Norrin is involved in Wnt signaling, particularly in the context of vascularization and retinal development.

They are distinct genes with different roles and mechanisms in development, even though their names sound similar.