Table 1.

Molecular structure and behavioral actions of mature gonadotropin-inhibitory hormone (GnIH) peptides identified in birds and mammals.

Vertebrates	Molecular structure of mature GnIH peptides	Receptor and cell signaling of mature GnIH peptides	Behavioral actions of mature GnIH peptides
Mammals	MPHSFANLPLRFa (human GnIH; RFRP-1) VPNLPQRFa (human GnIH; RFRP-3) SGRNMEVSLVRQVLNLPQRFa (macaque GnIH; RFRP-3) SLTFEEVKDWAPKIKMNKPVVNKMPPSAANLPLRFa (bovine GnIH; RFRP-1) AMAHLPLRLGKNREDSLSRWVPNLPQRFa (bovine GnIH; RFRP-3) ANMEAGTMSHFPSLPQRFa (rat GnIH; RFRP-3) SPAPANKVPHSAANLPLRFa (Siberian hamster GnIH; RFRP-1) TLSRVPSLPQRFa (Siberian hamster GnIH; RFRP-3)	GPR147 is the primary and GPR74 is the secondary receptor for human GnIH (human). Activation of GPR147 suppresses cAMP production (human). Mammalian GnIHs (RFRPs) suppress adenylate cyclase /cAMP/ protein kinase A-dependent extracellular signal-regulated kinase phosphorylation (mouse gonadotrope cell line). Gonadotropin-releasing hormone (GnRH) neurons express GPR147 (Siberian hamsters). GnRH neurons express GPR147 mRNA (mice). Kiss1 neurons express GPR147 and GPR74 mRNAs (mice). Gonadotropes express GPR147 mRNA (human).	Central administration of mammalian GnIH (RFRP-3) decreases male sex behavior (rats). Central administration of avian GnIH reduces sexual motivation and vaginal scent marking (female hamsters). Central administration of mammalian GnIHs (RFRPs) induces anxiety-related behavior (rats). Central administration of mammalian GnIH (RFRP-3) increases food intake (male rats, sheep). Bilateral intraamygdalar administration of mammalian GnIH (RFRP-3) decreases food intake (male rats). Bilateral intraamygdalar administration of mammalian GnIH (RFRP-1) has positive rewarding–reinforcing properties (male rats).
Birds	SIKPSAYLPLRFa (quail GnIH) SSIQSLLNLPQRFa (quail GnIH-RP-2) SIRPSAYLPLRFa (chicken GnIH) SIKPFANLPLRFa (European starling GnIH) SIKPFSNLPLRFa (zebra finch GnIH)	GPR147 is the primary receptor for avian GnIH (quail, chicken). Activation of GPR147 suppresses cAMP production (chicken). GnRH1 and GnRH2 neurons express GPR147 mRNA (starlings). GPR147 is colocalized with luteinizing hormone β or follicle-stimulating hormone β mRNA in the pituitary (chicken).	Central administration of avian GnIH inhibits copulation solicitation (female white-crowned sparrows). Avian GnIH RNA interference reduces resting time, spontaneous production of complex vocalizations, and stimulated brief agonistic vocalizations (white-crowned sparrows). Central administration of avian GnIH decreases socio-sexual behavior (male quail). Central administration of avian GnIH, GnIH-RP-1 and GnIH-RP-2 stimulates food intake (chicks). Central administration of avian GnIH stimulates feeding (adult Pekin drakes).

Names of the investigated species or organism are shown in the parenthesis.