Selective Degeneration and Sexual Dimorphism of Flight Muscles in Crickets

本实验主要研究了蟋蟀(Gryllus Bimaculatus DeGeer)成虫生活中飞行肌肉的选择性退化以及飞行肌肉和神经系统的性别二型性。女性M112a的生长和退化程度大于男性。M112a的变性首先发生在肌肉的腹侧，然后是背侧。支配M112a的运动神经元的切断导致M112a在两个部位同时变性。(2)成虫在想象换羽后24小时内断头，M112a几乎或未见变性。然而，M112a的选择性变性在断头的年轻成虫中可见，变成了…更多的是每天注射哪种JH激素，以及正常的年轻人。(3)在假想蜕皮后立即切断支配M112a的运动神经元，M112a的生长受到抑制，但失神经支配的M112a变性的时间与正常支配的M112a相似。(5)离子镧示踪实验清楚地表明，从血腔到精囊管腔和腺腔的角质层小管存在横向离子通道。较少

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