Physiological studies on the physiological and behavioral changes after mating in the moth, Bombyx mori

交配后信息素产生的抑制似乎是由一种神经信号引起的，该信号来自腹部并沿腹侧神经索上行，以抑制信息素性神经肽的释放。本研究表明，释放神经肽的神经分泌细胞对机械刺激最为敏感，其放电活动在交配开始后被完全抑制。因此，在交配过程中由物理刺激引起的机械信号可以触发神经分泌细胞的失活机制。因为与不育雄性交配未能诱导细胞的永久抑制。由机械刺激引起的暂时抑制，如果它们不能接收到另一个信号，可能是由精子和/或睾丸因子从有生育能力的男性转移而来。当从交配雌虫的交媾囊中获得的精液被人工注射到已经从不育雄虫那里接受了更多刺激的雌虫体内时，信息素的产生发生了永久性的抑制，从而表明性信息素产生的两步失活机制在交配雌虫中是正确的。从对交配的舞毒蛾的观察中推断出类似的两步失活机制。家蚕中假定的信息调节雄性因子的鉴定和作用方式仍有待确定。当雌性在交配后被固定在一个平台上时，信息素的产生通常会在交配后再次恢复。在95% CO_2麻醉15 min或乙醚麻醉1 ~ 2 min后，雌鼠信息素产生恢复情况相似。结果表明，在某些应激条件下，如约束或麻醉，永久性抑制可以被释放。未交配产卵的突变株（XU20），其性信息素含量很低，但脑-食道下神经节提取物中PBAN活性很高，这表明释放信息素性神经肽的神经分泌细胞即使在未交配的雌性体内也可能失活。少

Suppression of pheromone production after mating in moths seems to be induced by a neural signal that originates from the abdomen and runs up the ventral nerve cord to inhibit the release of pheromonotropic neuropeptides. The present study demonstrated that the neurosecretory cells releasing the neuropeptides were most sensitive to mechanical stimulation and their firing activities were completely suppressed as soon as mating began. Thus, a mechanical signal induced by physical stimulation during copulation can trigger an inactivation mechanism of the neurosecretory cells. Because mating with a sterile male failed to induce permanent suppression of the cells. a temporal inhibition caused by mechanical stimuli may be released if they cannot receive another signal that may be induced by the sperm and /or testicular factors transferred from a fertile male. When semen obtained from the bursa copulatorix of a mated female were artificially injected into a female which already received tacti … More le stimulation from a sterile male, permanent suppression of pheromone production occurred, thereby indicating that the two-step inactivation mechanism of sex pheromone production is true in a mated female.A similar two-step inactivation mechanism has been inferred from observations of mated gypsy moth.Identification and mode of action of the putative-pheromonostatic male factor in Bombyx mori remain to be determined.Pheromone production often resumed again in mated moths when the females were fixed to a platform after mating. Similar resumption of pheromone production were observed in the females which were anesthetized for 15 min in 95% CO_2 or for 1-2 min in etylether. The results suggest that the permanent suppressioncan be released under some stressful condition, such as restraint or anesthesia.Virgin females of a mutant strain (XU20), which lay eggs without mating, had very low amount of sex pheromone but had large amonunt of PBAN activity in the extract of the brain-suboesophageal ganglion, thereby suggesting that the neurosecretory cells releasing pheromonotropic neuropeptides may be inactivated even in a virgin female. Less