Regulation of larval corpora allata in Galleria mellonella
Regulation of larval corpora allata in Galleria mellonella
复制标题
大蜡螟幼虫幼体的调节
作者：
N. Granger;F. Sehnal
在昆虫中，当咽侧体停止分泌保幼激素时发生变态，但不知道保幼激素的产生是如何调节的。Wigglesperson 1首先指出，从大脑到咽侧体的神经连接提供了一种控制机制;这种控制可能是神经或神经激素的。在许多成年昆虫中，咽侧体似乎通过它们与大脑的神经连接而受到抑制，因为在大多数情况下，切断这些神经会激活腺体2，3。对于幼虫是否也是如此，还没有得到结论性的证明。通过神经分泌激活咽侧体已在许多成年昆虫中得到证实，例如黄粉虫2、马铃薯叶甲4和长刺红瓢虫5，并且幼虫脑产生异源激素也已被证实6 -8。我们现在已经调查了大蜡螟末龄幼虫的咽侧体功能的控制，这一发现鼓舞了我们，即在这个物种中，在末龄幼虫开始时植入大脑会导致额外的幼虫蜕皮9。我们的研究结果表明，咽侧体被激活的神经体液因子从幼虫发育过程中的大脑和它们是失活的神经抑制前变态。
IN insects metamorphosis occurs when the corpora allata stop secreting juvenile hormone, but it is not known how the production of juvenile hormone is regulated. Wigglesworth1 first indicated that the nervous connections from the brain to the corpora allata provide a mechanism for control; this control could be nervous or neurohormonal. In many adult insects, the corpora allata seem to be inhibited via their nervous connections to the brain, since in most cases severing these nerves activates the glands2,3. Whether the same is true for larvae has not been demonstrated conclusively. Activation of the corpora allata by neurosecretion has been demonstrated in many adult insects, for example Tenebrio molitor2, Leptinotarsa decemlineata4 and Rhodnius prolixus5, and the production of an allatotropic hormone by the larval brain has also been suggested6–8. We have now investigated the control of corpora allata function in last instar larvae of Galleria mellonella, encouraged by the discovery that in this species the implantation of brains at the beginning of the last larval instar causes an extra larval moult9. Our results show that the corpora allata are activated by a neurohumoral factor from the brain during larval development and that they are inactivated by nervous inhibition just before metamorphosis.