Data from: Regionalization of surface lipids in insects

Cuticular hydrocarbons (CHCs) play a critical role in the establishment of the waterproof barrier that prevents dehydration and wetting in insects. While rich data are available on CHC composition in different species, we know little about their distribution and organization. Here, we report on our studies of the surface barrier of the fruit fly Drosophila melanogaster applying a newly developed Eosin Y staining method. The inert Eosin Y penetrates different regions of the adult body at distinct temperatures. By contrast, the larval body takes up the dye rather uniformly and gradually with increasing temperature. Cooling down specimens to 25°C after incubation at higher temperatures restores impermeability. Eosin Y penetration is also sensitive to lipid solvents such as chloroform indicating that permeability depends on CHCs. As in D. melanogaster adult flies, Eosin Y penetration is regionalized in Tenebrio molitor larvae, whereas it is not in Locusta migratoria nymphs. Regionalization of the fly surface implies tissue-specific variation of the genetic or biochemical programmes of CHC production and deposition. The Eosin Y-based map of CHC distribution may serve to identify the respective factors that are activated to accommodate ecological needs.

表皮碳氢化合物（Cuticular hydrocarbons, CHCs）在昆虫构建抵御脱水与浸湿的防水屏障过程中发挥关键作用。尽管目前已有诸多关于不同物种CHC组成的详实数据，但我们对其分布模式与组织结构仍知之甚少。本文针对黑腹果蝇（Drosophila melanogaster）的体表屏障展开研究，采用了全新开发的伊红Y（Eosin Y）染色法。惰性染料伊红Y会在不同温度条件下，以区域特异性的方式渗透至成虫躯体的不同部位。与之形成鲜明对比的是，幼虫躯体对该染料的摄取则随温度升高呈现均匀且渐进的态势。将经高温孵育的样本冷却至25℃后，其屏障的不透性可得以恢复。伊红Y的渗透过程同样会受到氯仿等脂溶性溶剂的干扰，这表明该屏障的通透性依赖于CHCs。与黑腹果蝇成虫一致，黄粉虫（Tenebrio molitor）幼虫的体表伊红Y渗透同样呈现区域化特征，而东亚飞蝗（Locusta migratoria）若虫则未表现出该现象。果蝇体表的区域化渗透特征，意味着CHC的合成与沉积相关的遗传或生化程序存在组织特异性差异。基于伊红Y染色的CHC分布图谱，可为识别那些为适配生态需求而被激活的相关调控因子提供研究基础。