Ciliary defects cause several ciliopathies, some of which have late onset, suggesting cilia are actively maintained. Still, we have a poor understanding of the mechanisms underlying their maintenance. Here, we show Drosophila melanogaster IFT88 (DmIFT88/nompB) continues to move along fully formed sensory cilia. We further identify Inactive, a TRPV channel subunit involved in Drosophila hearing and negative-gravitaxis behaviour, and a yet uncharacterised Drosophila Guanylyl Cyclase 2d (DmGucy2d/CG34357) as DmIFT88 cargoes. We also show DmIFT88 binding to the cyclase´s intracellular part, which is evolutionarily conserved and mutated in several degenerative retinal diseases, is important for the ciliary localisation of DmGucy2d. Finally, acute knockdown of both DmIFT88 and DmGucy2d in ciliated neurons of adult flies caused defects in the maintenance of cilium function, impairing hearing and negative-gravitaxis behaviour, but did not significantly affect ciliary ultrastructure. We conclude that the sensory ciliary function underlying hearing in the adult fly requires an active maintenance program which involves DmIFT88 and at least two of its signalling transmembrane cargoes, DmGucy2d and Inactive.

中文翻译：

---

IFT88 通过沿着果蝇纤毛定位信号蛋白来维持感觉功能。

纤毛缺陷会导致多种纤毛病，其中一些发病较晚，表明纤毛得到积极维持。尽管如此，我们对其维护的机制仍知之甚少。在这里，我们展示了果蝇IFT88 ( Dm IFT88/nompB) 继续沿着完全形成的感觉纤毛移动。我们进一步鉴定出 Inactive（参与果蝇听力和负重力行为的TRPV 通道亚基）和尚未表征的果蝇鸟苷酸环化酶 2d ( Dm Gucy2d/CG34357) 作为Dm IFT88 货物。我们还表明，Dm IFT88 与环化酶细胞内部分的结合对于Dm Gucy2d的纤毛定位非常重要，该部分在进化上保守并在几种退行性视网膜疾病中发生突变。最后，在成年果蝇纤毛神经元中急性敲除Dm IFT88 和Dm Gucy2d 会导致纤毛功能维持缺陷，损害听力和负重力行为，但不会显着影响纤毛超微结构。我们得出的结论是，成年果蝇听力的感觉纤毛功能需要主动维护计划，其中涉及Dm IFT88 及其至少两种信号跨膜货物Dm Gucy2d 和 Inactive。