Nanopore Formation in the Cuticle of an Insect Olfactory Sensillum
Nanopore Formation in the Cuticle of an Insect Olfactory Sensillum
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DOI：
10.1016/j.cub.2019.03.043
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发表时间：
2019-05-06
期刊：
影响因子：
9.2
通讯作者：
Hayashi, Shigeo
中科院分区：
文献类型：
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作者：
Ando, Toshiya;Sekine, Sayaka;Hayashi, Shigeo
纳米级图案化表面结构形成生物功能的基础，包括超疏水性、结构着色和光吸收[1 - 3]。在昆虫中，覆盖在嗅觉感受器上的角质层具有多个小的（直径50至200 nm）孔[4 - 8]，这些孔应该起到过滤器的作用，允许气味分子进入，同时防止较大的空气颗粒进入并限制水分损失。然而，细胞外基质图案化成功能性纳米结构的细胞过程仍然未知。在这里，我们表明，表皮nanopores在果蝇嗅觉感受器起源于一个弯曲的nanopores膜，形成在最外层的包膜层的角质层和分泌从专门的突起在质膜的头发形成（nanopores）细胞。包膜曲率与胞吞结构相关的质膜波动一致。gore-tex/Osiris23基因编码一种内体蛋白，该蛋白对于包膜曲率、纳米孔形成和气味感受性是必需的，并且在发育中的嗅觉神经元细胞中特异性表达。由24个成员组成的Osiris基因家族在角质层分泌细胞中表达，仅在昆虫基因组中发现。这些结果揭示了气味接收的纳米孔的基本要求，并确定Osiris基因作为研究昆虫表面纳米制造进化的平台。
Nanometer-level patterned surface structures form the basis of biological functions, including superhy-drophobicity, structural coloration, and light absorption [1-3]. In insects, the cuticle overlying the olfactory sensilla has multiple small (50- to 200-nm diameter) pores [4-8], which are supposed to function as a filter that admits odorant molecules, while preventing the entry of larger airborne particles and limiting water loss. However, the cellular processes underlying the patterning of extracellular matrices into functional nano-structures remain unknown. Here, we show that cuticular nanopores in Drosophila olfactory sensilla originate from a curved ultrathin film that is formed in the outermost envelope layer of the cuticle and secreted from specialized protrusions in the plasma membrane of the hair forming (trichogen) cell. The envelope curvature coincides with plasma membrane undulations associated with endocytic structures. The gore-tex/Osiris23 gene encodes an endosomal protein that is essential for envelope curvature, nanopore formation, and odor receptivity and is expressed specifically in developing olfactory trichogen cells. The 24-member Osiris gene family is expressed in cuticle-secreting cells and is found only in insect genomes. These results reveal an essential requirement for nanopores for odor reception and identify Osiris genes as a platform for investigating the evolution of surface nano-fabrication in insects.