Plays a role as a potent and selective agonist of pth2r resulting in adenyl cyclase activation and intracellular calcium level elevation. Detected at the cleavage and blastula stages, 1.75-4 hours post-fertilization (hpf) (PubMed:21880859). Expressed in forebrain, midbrain, hindbrain and cells lining the brain ventricles at 19-22 hpf (PubMed:21880859). Expressed in midbrain and otic vesicles at 26-36 hpf (PubMed:21880859). Detected in bilateral domains in brain near the hypothalamus, and in heart, at 48-72 hpf (PubMed:15297442, PubMed:21880859). Up-regulated in the developing brain by shh signaling. Belongs to the parathyroid hormone family. Unlikely isoform. Aberrant splice sites.