“…In 2000, we provided a new concept on the basis of the discovery of gonadotropin-inhibitory hormone (GnIH), a hypothalamic neuropeptide that actively reduces gonadotropin release, in quail (Tsutsui et al, 2000a). The follow-up studies demonstrated that GnIH is highly conserved among vertebrates, from agnathans to humans, and that it acts as a key player for regulation of reproduction (for reviews, see Kriegsfeld et al, 2015;Tsutsui, 2009;Tsutsui and Ubuka, 2012;Tsutsui and Ukena, 2006;Tsutsui et al, 2006bTsutsui et al, , 2007Tsutsui et al, , 2010aTsutsui et al, ,b, 2012bTsutsui et al, , 2013dUkena and Tsutsui, 2005). In addition, recent studies have demonstrated that GnIH has other important functions beyond reproduction Ubuka et al, 2014).…”