Minami Ryunosuke, Sato Chiaki, Yamahama Yumi, Kubo Hideo, Hariyama Takahiko, Kimura Ken-Ichi
1 Laboratory of Biology, Hokkaido University of Education, Sapporo Campus, Sapporo 002-8502, Japan.
2 Department of Biology, Hamamatsu University School of Medicine, Hamamatsu 431-3192, Japan.
Zoolog Sci. 2016 Dec;33(6):583-591. doi: 10.2108/zs160105.
The "moth-eye" structure, which is observed on the surface of corneal lens in several insects, supports anti-reflective and self-cleaning functions due to nanoscale protrusions known as corneal nipples. Although the morphology and function of the "moth-eye" structure, are relatively well studied, the mechanism of protrusion formation from cell-secreted substances is unknown. In Drosophila melanogaster, a compound eye consists of approximately 800 facets, the surface of which is formed by the corneal lens with nanoscale protrusions. In the present study, we sought to identify genes involved in "moth-eye" structure, formation in order to elucidate the developmental mechanism of the protrusions in Drosophila. We re-examined the aberrant patterns in classical glossy-eye mutants by scanning electron microscope and classified the aberrant patterns into groups. Next, we screened genes encoding putative structural cuticular proteins and genes involved in cuticular formation using eye specific RNAi silencing methods combined with the Gal4/UAS expression system. We identified 12 of 100 candidate genes, such as cuticular proteins family genes (Cuticular protein 23B and Cuticular protein 49Ah), cuticle secretion-related genes (Syntaxin 1A and Sec61 ββ subunit), ecdysone signaling and biosynthesis-related genes (Ecdysone receptor, Blimp-1, and shroud), and genes involved in cell polarity/cell architecture (Actin 5C, shotgun, armadillo, discs large1, and coracle). Although some of the genes we identified may affect corneal protrusion formation indirectly through general patterning defects in eye formation, these initial findings have encouraged us to more systematically explore the precise mechanisms underlying the formation of nanoscale protrusions in Drosophila.
在几种昆虫的角膜晶状体表面观察到的“蛾眼”结构，由于被称为角膜乳头的纳米级突起而具有抗反射和自清洁功能。尽管对“蛾眼”结构的形态和功能已有相对充分的研究，但细胞分泌物质形成突起的机制尚不清楚。在黑腹果蝇中，复眼由大约800个小眼面组成，其表面由具有纳米级突起的角膜晶状体形成。在本研究中，我们试图鉴定参与“蛾眼”结构形成的基因，以阐明果蝇中突起的发育机制。我们通过扫描电子显微镜重新检查了经典亮眼突变体中的异常模式，并将这些异常模式进行了分类。接下来，我们使用眼部特异性RNAi沉默方法结合Gal4/UAS表达系统，筛选了编码假定结构表皮蛋白的基因和参与表皮形成的基因。我们从100个候选基因中鉴定出了12个，如表皮蛋白家族基因（表皮蛋白23B和表皮蛋白49Ah）、表皮分泌相关基因（Syntaxin 1A和Sec61ββ亚基）、蜕皮激素信号传导和生物合成相关基因（蜕皮激素受体、Blimp-1和shroud），以及参与细胞极性/细胞结构的基因（肌动蛋白5C、shotgun、犰狳、盘大蛋白1和coracle）。尽管我们鉴定出的一些基因可能通过眼睛形成中的一般模式缺陷间接影响角膜突起的形成，但这些初步发现鼓励我们更系统地探索果蝇中纳米级突起形成的精确机制。
