Selective Degeneration and Sexual Dimorphism of Flight Muscles in Crickets

本实验主要研究了蟋蟀（Gryllus bimaculatus DeGeer）成年期飞行肌的选择性退化及飞行肌和神经系统的两性异形。结果表明：（1）后胸间接飞行肌（M112a）在成虫蜕皮后的前3天内显著生长，肌肉质量达到最大值后不久开始退化。M112a在雌虫体内的生长和退化程度大于雄虫。M112a的变性首先发生在肌肉的腹侧部分，然后在背侧部分。支配M112a的运动神经元的切断导致M112a在两个部分的同时变性。(2)在成虫蜕皮后24小时内，将年轻成虫斩首，M112a几乎没有或没有可见的变性。然而，M112a的选择性变性在被斩首的年轻成年人中是可见的， 关于我们 每天注射的JH激素，以及正常的年轻人。(3)当支配M112a的运动神经元在成虫蜕皮后立即被切断时，M112a的生长受到抑制，但失神经支配的M112a的退化时间与正常支配的M112a的退化时间相似。(4)直接飞行肌M90的机械活动存在明显的性二型性，但支配M90的运动神经元在形态特征上没有明显的性二型性。(5)使用离子镧的示踪实验清楚地表明存在横向离子通道，通过表皮小管从血腔到受精囊管和腺腔的管腔。(6)行为学实验表明，雄蟋蟀交配行为的发展是一个基本运动模式增强的过程，而不是通过中枢神经系统模式产生回路的变化增加新动作的过程。少

The present experiments were designed to study mainly the selective degeneration of flight muscles during adult life and sexual dimorphism of flight muscles and nervous system in the cricket (Gryllus bimaculatus DeGeer). The results obtained were as follows : (1) The metathoracic indirect flight muscle (M112a) grew significantly during the first 3 days after the imaginal moult ; soon after muscle mass reached its maximum value, it began to degenerate. The degree of growth and degeneration of M112a in the female was greater than in the male. The degeneration of M112a occurred first in the ventral part of the muscle, and then in the dorsal part. The severance of the motoneurons innervating M112a resulted in the simultaneous degeneration of M112a in both parts. (2) When the young adult was decapitated within 24 hours after the imaginal moult, there was little or no degeneration of M112a visible. The selective degeneration of M112a, however, was visible in the decapitated young adult, into … More which JH hormone was injected daily, as well as in the normal young adults. (3) When the motoneurons innervating M112a were severed immediately after the imaginal moult, the growth of M112a was suppressed, but the timing of degeneration of the denervated M112a was similar to that of the normally innervated M112a. (4) It was evident that there was the sexual dimorphism in the mechanical activity of the direct flight muscle, M90, but the motoneurons innervating M90 did not show significant sexual dimorphism in their morphological characteristics. (5) The tracer experiment using ionic lanthanum clearly demonstrated the presence of transverse ionic passages through the cuticular ductules from the haemocoel to the lumen of the spermathecal duct and glandular cavities. (6) Behavioral experiment showed that the development of mating behavior in the male cricket is a process of enhancement of basic motor patters but not a process of addition of new movements by changes in pattern generation circuits in the central nervous system. Less