Ockleford E M, Vince M A
J Comp Physiol Psychol. 1980 Apr;94(2):280-8. doi: 10.1037/h0077674.
Development of chick embryos was studied following injection of thyroxine or the goitrogen thiourea and compared with that in control saline-injected eggs. The three stages recorded (onset of beak clapping, clicking, and hatching movements) all occurred late in embryos treated with thiourea on the 16th day of incubation. Thyroxine-treated eggs hatched significantly early only when incubated in groups in contact. This suggests that an acceleration effect of thyroxine reported in previous work may have represented an unreliable effect of thyroxine coupled with the synchronizing effect of contact with other eggs. Changes in hatching times following hormone injection are compared with these associated with effects of clicks, which are known to regulate developmental rate and to play a part in the synchronization of hatching.
在给鸡胚注射甲状腺素或致甲状腺肿物质硫脲后，对鸡胚的发育进行了研究，并与注射生理盐水的对照蛋进行了比较。记录的三个阶段（啄击、轻叩和孵化动作的开始）在孵化第16天用硫脲处理的胚胎中都出现得较晚。只有在成群接触孵化时，经甲状腺素处理的蛋才会显著提前孵化。这表明，先前研究中报道的甲状腺素的加速作用可能是甲状腺素的不可靠作用与与其他蛋接触的同步作用的结合。将激素注射后孵化时间的变化与已知可调节发育速度并在孵化同步中起作用的轻叩效应相关的变化进行了比较。
