A new key neurohormone controlling reproduction, gonadotrophin-inhibitory hormone in birds: discovery, progress and prospects.
In vertebrates, the neuropeptide control of gonadotrophin secretion is primarily through the stimulatory action of the hypothalamic decapeptide, gonadotrophin-releasing hormone (GnRH). Gonadal sex steroids and inhibin inhibit gonadotrophin secretion via feedback from the gonads, but a hypothalamic neuropeptide inhibiting gonadotrophin secretion was, until recently, unknown in vertebrates. In 2000, we discovered a novel hypothalamic dodecapeptide that directly inhibits gonadotrophin release in quail and termed it gonadotrophin-inhibitory hormone (GnIH). GnIH acts on the pituitary and GnRH neurones in the hypothalamus via a novel G-protein-coupled receptor for GnIH to inhibit gonadal development and maintenance by decreasing gonadotrophin release and synthesis. The pineal hormone melatonin is a key factor controlling GnIH neural function. GnIH occurs in the hypothalamus of several avian species and is considered to be a new key neurohormone inhibiting avian reproduction. Thus, the discovery of GnIH provides novel directions to investigate neuropeptide regulation of reproduction. This review summarises the discovery, progress and prospects of GnIH, a new key neurohormone controlling reproduction.
Tsutsui
K
K
Department of Biology, Waseda University, Tokyo, Japan. k-tsutsui@waseda.jp
Saigoh
E
E
Yin
H
H
Ubuka
T
T
Chowdhury
V S
VS
Osugi
T
T
Ukena
K
K
Sharp
P J
PJ
Wingfield
J C
JC
Bentley
G E
GE
D000818:Animals; D030161:Avian Proteins / Q000302:isolation & purification* / Q000378:metabolism*; D001717:Birds; D003370:Coturnix; D006062:Gonadotropins / Q000378:metabolism*; D006066:Gonads / Q000254:growth & development; D007028:Hypothalamic Hormones / Q000302:isolation & purification* / Q000378:metabolism*; D007031:Hypothalamus / Q000378:metabolism; D008550:Melatonin / Q000378:metabolism; D009474:Neurons / Q000378:metabolism; D010902:Pituitary Gland / Q000378:metabolism; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism; D012098:Reproduction / Q000502:physiology
D030161:Avian Proteins; D006062:Gonadotropins; D007028:Hypothalamic Hormones; D043562:Receptors, G-Protein-Coupled; C413752:gonadotropin-inhibitory hormone, Coturnix japonica; D008550:Melatonin