Which of the following has impoant role in initiation and maintenance of primitive streak: (A) FGF-8, (B) BMP-4, (C) EGRF, (D) Nodal gene
Answer is D. D i.e. Nodal gene The primitive streak is initiated and maintained by expression of nodal, a member of transforming growth factor /3 (TGF - 13) superfamilyQ.