Department of Biological Sciences, Tokyo Metropolitan University, Tokyo, 192-0397, Japan.
Department of Biological Sciences, Tokyo Metropolitan University, Tokyo, 192-0397, Japan.
Insect Biochem Mol Biol. 2019 May;108:61-70. doi: 10.1016/j.ibmb.2019.03.007. Epub 2019 Mar 20.
Insects are often regarded as the most successful group of animals in the terrestrial environment. Their success can be represented by their huge biomass and large impact on ecosystems. Among the factors suggested to be responsible for their success, we focus on the possibility that the cuticle might have affected the process of insects' evolution. The cuticle of insects, like that of other arthropods, is composed mainly of chitin and structural cuticle proteins. However, insects seem to have evolved a specific system for cuticle formation. Oxidation reaction of catecholamines catalyzed by a copper enzyme, laccase, is the key step in the metabolic pathway for hardening of the insect cuticle. Molecular phylogenetic analysis indicates that laccase functioning in cuticle sclerotization has evolved only in insects. In this review, we discuss a theory on how the insect-specific "laccase" function has been advantageous for establishing their current ecological position as terrestrial animals.
昆虫通常被认为是陆地环境中最成功的动物群体。它们的成功可以体现在巨大的生物量和对生态系统的巨大影响上。在被认为是导致它们成功的因素中，我们关注的是外骨骼可能影响昆虫进化过程的可能性。昆虫的外骨骼，与其他节肢动物一样，主要由几丁质和结构外骨骼蛋白组成。然而，昆虫似乎已经进化出了一种特定的外骨骼形成系统。儿茶酚胺的氧化反应被铜酶漆酶催化，是昆虫外骨骼硬化代谢途径中的关键步骤。分子系统发育分析表明，在角质硬化中起作用的漆酶仅在昆虫中进化。在这篇综述中，我们讨论了一种理论，即昆虫特有的“漆酶”功能是如何有利于它们确立当前作为陆地动物的生态地位的。
