Gonadotropin-releasing hormones (GnRH) are the key factors stimulating gonadotropin release from the pituitary. GnRHs are decapeptides that act via G-protein coupled receptors (gonadotropin-releasing hormone receptors, GnRH-R). To date, several molecular forms of GnRH and GnRH-R have been identified in vertebrates. In most species, two forms of GnRH are present. one that is hypophysiotropic, stimulating gonadotropin release from the pituitary, and one that plays a neuromodulatory role in the central nervous system. The pituitary gonadotropins are heterodimeric glycoprotein-hormones consisting of a non-covalently linked common glycoprotein-hormone α-subunit and a specific β-subunit (FSHβ or LHβ) conferring their biological activity(2) ebd c6d gonadotropin releasing neuron CL:0011111 Cell Ontology signaling pathway PW:0000003 Pathway Ontology 24246134 PubMed A systems biology approach using metabolomic data reveals genes and pathways interacting to modulate divergent growth in cattle. BMC Genomics 2013 Widmann P Reverter A Fortes MR Weikard R Suhre K Hammon H Albrecht E Kuehn C 17710727 PubMed Regulation of gonadotropin-releasing hormone gene expression. Semin Reprod Med 2007 Kim HH