Dobens Leonard L, Shipman Anna, Axelrod Jeffrey D
a Division of Molecular Biology and Biochemistry, School of Biological Sciences , University of Missouri-Kansas City , Kansas City , MO , USA.
b Department of Pathology , Stanford University School of Medicine , Stanford , CA , USA.
Fly (Austin). 2018 Jan 2;12(1):23-33. doi: 10.1080/19336934.2017.1409927. Epub 2017 Dec 22.
Epithelial cells are defined by apical-basal and planar cell polarity (PCP) signaling, the latter of which establishes an orthogonal plane of polarity in the epithelial sheet. PCP signaling is required for normal cell migration, differentiation, stem cell generation and tissue repair, and defects in PCP have been associated with developmental abnormalities, neuropathologies and cancers. While the molecular mechanism of PCP is incompletely understood, the deepest insights have come from Drosophila, where PCP is manifest in hairs and bristles across the adult cuticle and organization of the ommatidia in the eye. Fly wing cells are marked by actin-rich trichome structures produced at the distal edge of each cell in the developing wing epithelium and in a mature wing the trichomes orient collectively in the distal direction. Genetic screens have identified key PCP signaling pathway components that disrupt trichome orientation, which has been measured manually in a tedious and error prone process. Here we describe a set of image processing and pattern-recognition macros that can quantify trichome arrangements in micrographs and mark these directly by color, arrow or colored arrow to indicate trichome location, length and orientation. Nearest neighbor calculations are made to exploit local differences in orientation to better and more reliably detect and highlight local defects in trichome polarity. We demonstrate the use of these tools on trichomes in adult wing preps and on actin-rich developing trichomes in pupal wing epithelia stained with phalloidin. FijiWingsPolarity is freely available and will be of interest to a broad community of fly geneticists studying the effect of gene function on PCP.
上皮细胞由顶-基和平面细胞极性（PCP）信号通路所定义，后者在上皮细胞层中建立了一个正交的极性平面。PCP信号通路对于正常的细胞迁移、分化、干细胞生成和组织修复是必需的，而PCP缺陷与发育异常、神经病理学和癌症有关。虽然PCP的分子机制尚未完全了解，但最深入的见解来自果蝇研究，在果蝇中，PCP表现为成虫表皮上的刚毛和鬃毛以及眼睛中复眼的组织排列。果蝇翅膀细胞的特征是在发育中的翅膀上皮细胞的每个细胞远端边缘产生富含肌动蛋白的毛状体结构，在成熟翅膀中，毛状体集体向远端方向定向。遗传筛选已经确定了破坏毛状体定向的关键PCP信号通路成分，而毛状体定向是通过一个繁琐且容易出错的手动过程来测量的。在这里，我们描述了一组图像处理和模式识别宏程序，它们可以量化显微照片中的毛状体排列，并直接用颜色、箭头或彩色箭头标记这些排列，以指示毛状体的位置、长度和方向。通过最近邻计算来利用方向上的局部差异，以更好、更可靠地检测和突出毛状体极性的局部缺陷。我们展示了这些工具在成年翅膀标本的毛状体以及用鬼笔环肽染色的蛹期翅膀上皮细胞中富含肌动蛋白的发育中的毛状体上的应用。FijiWingsPolarity是免费提供的，将对广大研究基因功能对PCP影响的果蝇遗传学家群体有吸引力。
