<prompt> Which of the following inhibits hea development?NKX2.5WNTBMPNone of the above  <response>: Signals from anterior cranial endoderm induce a hea-forming region in overlying splanchnic mesoderm by inducing the transcription factor NKX2.5. The signals require secretion of BMPs 2 and 4 secreted by the endoderm and lateral plate mesoderm. Concomitantly, the activity of WNT proteins 3a and 8 secreted by the neural tube, must be blocked because they normally inhibit hea development. Inhibitors crescent and cerberus of the WNT proteins are produced by endoderm cells immediately adjacent to hea-forming mesoderm in the anterior half of the embryo. The combination of bone morphogenetic protein BMP activity and WNT inhibition by crescent and cerberus causes expression of NKX2.5, the master gene for hea development. BMP expression also up regulates expression of FGF8 that is impoant for the expression of cardiac-specific proteins. Ref: Langmans embryology 11th edition Chapter 12. 