Tan Su Ee, Strutt David
School of Biosciences, University of Sheffield, Firth Court, Sheffield, UK.
Nat Commun. 2025 Feb 7;16(1):1451. doi: 10.1038/s41467-025-56744-7.
Planar polarity establishment in epithelia requires interpretation of directional tissue-level information at cellular and molecular levels. Mechanical forces exerted during tissue morphogenesis are emerging as crucial tissue-level directional cues, yet the mechanisms by which they regulate planar polarity are poorly understood. Using the Drosophila pupal wing, we confirm that tissue stress promotes proximal-distal (PD) planar polarity alignment. Moreover, high tissue stress anisotropy can reduce the rate of accumulation and lower the stability on cell junctions of the core planar polarity protein Frizzled (Fz). Notably, under high tissue stress anisotropy, we see an increased gradient of cell flow, characterised by differential velocities across adjacent cell rows. This promotes core protein turnover at cell-cell contacts parallel to the flow direction, possibly via dissociation of transmembrane complexes by shear forces. We propose that gradients of cell flow play a critical role in establishing and maintaining PD-oriented polarity alignment in the developing pupal wing.
上皮细胞中平面极性的建立需要在细胞和分子水平上解读组织水平的方向信息。组织形态发生过程中施加的机械力正成为关键的组织水平方向线索，但其调节平面极性的机制仍知之甚少。利用果蝇蛹翅，我们证实组织应力促进近端-远端（PD）平面极性排列。此外，高组织应力各向异性会降低核心平面极性蛋白卷曲蛋白（Fz）在细胞连接处的积累速率并降低其稳定性。值得注意的是，在高组织应力各向异性条件下，我们观察到细胞流动梯度增加，其特征是相邻细胞排之间的速度差异。这可能通过剪切力使跨膜复合物解离，从而促进与流动方向平行的细胞-细胞接触处的核心蛋白周转。我们提出，细胞流动梯度在发育中的蛹翅建立和维持PD取向的极性排列中起关键作用。
