AN ULTRASTRUCTURAL-STUDY OF THE INTEGUMENT DURING THE MOLT CYCLE OF THE WOODLOUSE, ONISCUS-ASELLUS (CRUSTACEA, ISOPODA)
AN ULTRASTRUCTURAL-STUDY OF THE INTEGUMENT DURING THE MOLT CYCLE OF THE WOODLOUSE, ONISCUS-ASELLUS (CRUSTACEA, ISOPODA)
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DOI：
10.1007/bf00998125
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发表时间：
1980-01-01
期刊：
影响因子：
--
通讯作者：
HOLDICH, DM
中科院分区：
文献类型：
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作者：
PRICE, JB;HOLDICH, DM
木虱是唯一的节肢动物在蜕皮中的两个一半。O. asellus，并导致从2半是在整个周期的同步。在珠被中，表皮细胞空泡化预示着一个新的蜕皮周期的开始;随后，表皮下组织增殖，巨噬细胞短暂出现。角质层按顺序产生，从上表皮结构如三角和斑块开始，然后是双相上表皮，片状蜕皮前角质层，以及蜕皮后的片状蜕皮后角质层。上表皮沿着表皮远端膜形成连续的片状结构，下表皮由细胞体内形成的纤维构成，这两个特征在其他节肢动物中未见报道。就在蜕皮之前，上表皮和蜕皮前角质层呈高度波纹状，并且随着新角质层成分略微撤回旧角质层下方而增加蜕皮间隙的宽度，表皮非常收缩。在这个时候，虽然蜕皮膜仍然很明显，但两个表皮之间的空间似乎没有曾经占据它的液体。蜕皮后，由于发生化学事件，上表皮的外观发生变化，这使得它相对不可渗透。此时，由于膨胀的物理应力，蜕皮前角质层的外观也发生变化。与其他甲壳纲动物相似，大的角质层前体囊泡特别与后期角质层的产生有关。也有许多与蜕皮前角质层形成有关的小泡。表皮的空泡随着后表皮角质层的产生而消失，当后表皮角质层形成时，表皮又变成一个狭窄的细胞层。该过程结束后立即发生细胞解体，不久之后周期重新开始。与其他节肢动物不同的是，木虱不会通过扩张来挣脱旧的角质层;相反，它们会离开1/2然后扩张。实验证据表明，木虱不采取水来实现这种扩张，而是出现雇用内部静水压力。利用已发表的数据从woodlice内分泌学研究以及目前的工作，激素控制的双相蜕皮的一种可能的方法。
Woodlice are unique among the arthropods in molting in 2 halves. The intramolt is 1.8 days in O. asellus, and results from the 2 halves being out of synchrony throughout the cycle. In the integument the initiation of a new molt cycle is heraled by epidermal cell vacuolation; later, the subepidermal tissue proliferates, and macrophages appear briefly. The cuticle layers are produced in order, starting with epicuticular structrues such as tricorns and plaques, followed by the biphasic epicuticle, the lamellate pre-ecdysial cuticle and, after ecdysis, the lamellate postecdysial cuticle. Epicuticle is formed in a continuous sheet along the distal epidermal membrane, and postecdysial cuticle from fibers formed within the cell body.sbd.both features not reported for other arthropods. Immediately prior to ecdysis, the epicuticle and pre-ecdysial cuticle are highly corrugated and the epidermis very constricted as the width of the ecdysing gap is increased by the new cuticle components withdrawing slightly beneath the old cuticle. At this time the space between the 2 cuticles appears devoid of the fluid that once occupied it, although the ecdysial membrane is still apparent. After ecdysis the appearance of the epicuticle changes due to chemical events occur, which make it relatively impermeable. At this time the pre-ecdysial cuticle also changes in appearance due to the physical stress of expansion. Large cuticle precursor vesicles, similar to those of other Crustacea, are particularly associated with postecdysial cuticle production. There are also numerous small vesicles associated with pre-ecdysial cuticle formation. The epidermal vacuoles disappear as postecdysial cuticle is produced so that, when it is complete, the epidermis is again a narrow cell layer. Apolysis occurs straight after this process, and shortly afterwards the cycle recommences. Unlike other arthropods, woodlice do not expand to break free of the old cuticle; instead they walk free of either 1/2 and then expand. Experimental evidence is given which suggests that woodlice do not take in water to achieve this expansion, but rather appear to employ internal hydrostatic pressure. Using published data from woodlice endocrinological studies as well as the present work, a possible method of hormonal control of the biphasic molt is suggested.