Halberg Kenneth A, Rainey Stephanie M, Veland Iben R, Neuert Helen, Dornan Anthony J, Klämbt Christian, Davies Shireen-Anne, Dow Julian A T
Institute of Molecular, Cell and Systems Biology, College of Medical, Veterinary and Life Sciences, University of Glasgow, Davidson Building Room 324, Glasgow G12 8QQ, UK.
Section for Cell &Neurobiology, Department of Biology, University of Copenhagen, Universitetsparken 15, Copenhagen DK-2100, Denmark.
Nat Commun. 2016 Apr 13;7:11266. doi: 10.1038/ncomms11266.
Multicellular organisms rely on cell adhesion molecules to coordinate cell-cell interactions, and to provide navigational cues during tissue formation. In Drosophila, Fasciclin 2 (Fas2) has been intensively studied due to its role in nervous system development and maintenance; yet, Fas2 is most abundantly expressed in the adult renal (Malpighian) tubule rather than in neuronal tissues. The role Fas2 serves in this epithelium is unknown. Here we show that Fas2 is essential to brush border maintenance in renal tubules of Drosophila. Fas2 is dynamically expressed during tubule morphogenesis, localizing to the brush border whenever the tissue is transport competent. Genetic manipulations of Fas2 expression levels impact on both microvilli length and organization, which in turn dramatically affect stimulated rates of fluid secretion by the tissue. Consequently, we demonstrate a radically different role for this well-known cell adhesion molecule, and propose that Fas2-mediated intermicrovillar homophilic adhesion complexes help stabilize the brush border.
多细胞生物依靠细胞粘附分子来协调细胞间的相互作用，并在组织形成过程中提供导航线索。在果蝇中，由于Fasciclin 2（Fas2）在神经系统发育和维持中的作用，它已被深入研究；然而，Fas2在成年肾（马尔皮基）小管中表达最为丰富，而非在神经组织中。Fas2在这种上皮组织中的作用尚不清楚。在这里，我们表明Fas2对于果蝇肾小管刷状缘的维持至关重要。Fas2在小管形态发生过程中动态表达，每当组织具备运输能力时就定位于刷状缘。对Fas2表达水平的基因操作会影响微绒毛的长度和组织，进而显著影响组织刺激的液体分泌速率。因此，我们证明了这种著名的细胞粘附分子具有截然不同的作用，并提出Fas2介导的微绒毛间嗜同性粘附复合物有助于稳定刷状缘。
