Bédécarrats Grégoy Y
Department of Animal and Poultry Science, University of Guelph, Guelph, ON, N1G 2W1 Canada
Poult Sci. 2015 Apr;94(4):810-5. doi: 10.3382/ps/peu042. Epub 2015 Jan 30.
As for most vertebrates, reproduction in poultry is controlled by an integrated axis [the hypothalamo-pituitary-gonadal (HPG) axis]. External and internal cues are integrated at the level of the hypothalamus to initiate gonadal recruitment and control the subsequent reproductive cycle. Until recently, it was believed that the HPG was exclusively under stimulatory control from hypothalamic gonadotropin releasing hormone (GnRH). However in 2000, the discovery of gonadotropin inhibitory hormone (GnIH), an inhibitory peptide, changed this dogma. Since then, evidence accumulated to confirm that in fact the HPG is under a dual control system with a stimulatory and an inhibitory branch. In this paper, we review the organization of this dual control system, the mechanisms controlling the synthesis and release of GnRH and GnIH, and the possible integration and interactions between the two branches to regulate pituitary gonadotropes' function. Furthermore, as light perception and photoperiod are the primary cues utilized by the poultry industry in controlled environments, special consideration was given to potential practical applications.
与大多数脊椎动物一样，家禽的繁殖受一个整合轴[下丘脑-垂体-性腺（HPG）轴]控制。外部和内部信号在下丘脑水平整合，以启动性腺募集并控制随后的繁殖周期。直到最近，人们一直认为HPG仅受下丘脑促性腺激素释放激素（GnRH）的刺激控制。然而，2000年促性腺激素抑制激素（GnIH）这一抑制性肽的发现改变了这一教条。从那时起，积累的证据证实，事实上HPG处于一个具有刺激和抑制分支的双重控制系统之下。在本文中，我们综述了这个双重控制系统的组织、控制GnRH和GnIH合成与释放的机制，以及两个分支之间可能的整合和相互作用，以调节垂体促性腺细胞的功能。此外，由于光照感知和光周期是家禽业在可控环境中利用的主要信号，因此特别考虑了潜在的实际应用。
