Holland Chase, Cox Natalya, Dery Hanna, Williams Mariah, Jones Gwendolyn, Newton Lindi, Jurgensen Kristin, Chang Han, Hord Alex, Chang Won, Montgomery Damon, Hochstedler Hawkins, Mishra Amish, Baker Jessica
Department of Biology, Taylor University, Upland, Indiana, United States of America.
Department of Mathematics, Taylor University, Upland, Indiana, United States of America.
PLoS One. 2025 Jul 23;20(7):e0328970. doi: 10.1371/journal.pone.0328970. eCollection 2025.
Planar cell polarity, polarization in the plane of an epithelium, is critical for tissue development. The Drosophila melanogaster wing epithelium is an important model system for planar cell polarity establishment and has greatly informed studies in vertebrates. The well-studied Frizzled-dependent and Fat - Dachsous - Four-jointed pathways establish proximal-to-distal polarity of wing hairs, while a Frizzled-independent mechanism mediated by septate junction proteins Gliotactin, Coracle, and Varicose is required for parallel alignment of neighboring hairs. In this study, we explore a requirement for the non-muscle myosin II proteins Spaghetti Squash and Zipper in wing hair planar cell polarity. We confirm a previously recognized role in hair initiation and demonstrate a second, novel Gliotactin-interacting requirement for spaghetti squash and zipper in parallel alignment. Immunolabeling experiments demonstrate that Spaghetti Squash and Zipper localize to the base of the developing hairs during the same time frame that septate junction proteins transiently relocalize to the apical cell surface. This localization is abrogated in Gliotactin loss-of-function genotypes. We propose that Gliotactin promotes Spaghetti Squash and Zipper accumulation at the cell apical surface during wing hair extension and that this apical Myosin-II complex stabilizes the developing hair base, maintaining parallel alignment of neighboring wing hairs.
平面细胞极性，即上皮平面中的极化，对于组织发育至关重要。黑腹果蝇翅膀上皮是平面细胞极性建立的重要模型系统，为脊椎动物的研究提供了很多信息。经过充分研究的卷曲蛋白依赖途径和Fat-Dachsous-四关节蛋白途径建立了翅毛的近端到远端极性，而由分隔连接蛋白Gliotactin、Coracle和曲张蛋白介导的一种不依赖卷曲蛋白的机制对于相邻翅毛的平行排列是必需的。在本研究中，我们探究了非肌肉肌球蛋白II蛋白Spaghetti Squash和Zipper在翅毛平面细胞极性中的需求。我们证实了其在翅毛起始中先前已被认识到的作用，并证明了Spaghetti Squash和Zipper在平行排列中对Gliotactin存在第二种新的相互作用需求。免疫标记实验表明，在分隔连接蛋白短暂重新定位到细胞顶端表面的同一时间框架内，Spaghetti Squash和Zipper定位于发育中翅毛的基部。这种定位在Gliotactin功能丧失基因型中被消除。我们提出，Gliotactin在翅毛延伸过程中促进Spaghetti Squash和Zipper在细胞顶端表面的积累，并且这种顶端肌球蛋白II复合体稳定发育中的翅毛基部，维持相邻翅毛的平行排列。
