Universitet Göteborg, Sahlgrenska Academy, Institute for Biomedicine, Box 440, 40530 Göteborg, Sweden.
Insect Biochem Mol Biol. 2010 May;40(5):363-75. doi: 10.1016/j.ibmb.2010.03.003. Epub 2010 Mar 27.
Insects possess a cuticle that covers all tissues exposed to the outside world including the body, the fore- and hindgut and the luminal side of the tracheae. The cuticle is a multifunctional device that protects its carriers against dehydration, arms them against predators, constitutes a physical barrier to prevent pathogen entry and serves as an exoskeleton allowing locomotion. Depending the developmental stage and the body part, the composition and function of the cuticle changes. The body cuticle of larvae of holometabolous insects for example is soft while their cuticular head skeletons used to chew food is hard. In spite of these differences, the basic architecture of the insect cuticle is evolutionarily well conserved between developmental stages and between species. The insect larval cuticle is formed at the apical site of a monolayer of polarised epithelial cells that differentiate concomitantly during embryogenesis. The stratified structure of the cuticle results from the concerted unfolding of basic cellular functions including timed transcription, biosynthetic enzymatic cascades, secretion and membrane trafficking as well as elaborate extracellular self-organization of the components. The aim of this review is to summarize recent advances in understanding these processes.
昆虫具有覆盖暴露于外界的所有组织的外骨骼，包括身体、前肠和后肠以及气管的腔侧。外骨骼是一种多功能的装置，保护其载体免受脱水、抵御捕食者、构成防止病原体进入的物理屏障，并作为允许运动的外骨骼。根据发育阶段和身体部位的不同，外骨骼的组成和功能会发生变化。例如，完全变态昆虫的幼虫体壁柔软，而用于咀嚼食物的角质头部骨骼坚硬。尽管存在这些差异，但昆虫外骨骼的基本结构在发育阶段和物种之间在进化上是很好地保守的。昆虫幼虫外骨骼是在极化上皮细胞的单层的顶端部位形成的，这些细胞在胚胎发生过程中同时分化。外骨骼的分层结构是由基本细胞功能的协同展开产生的，包括定时转录、生物合成酶级联、分泌和膜运输以及成分的精细细胞外自组织。本综述的目的是总结理解这些过程的最新进展。
