Biological tubes must develop and maintain their proper diameter to transport materials efficiently. These tubes are molded and protected in part by apical extracellular matrices (aECMs) that line their lumens. Despite their importance, aECMs are difficult to image in vivo and therefore poorly understood. The Caenorhabditis elegans vulva has been a paradigm for understanding many aspects of organogenesis. Here we describe the vulva luminal matrix, which contains chondroitin proteoglycans, Zona Pellucida (ZP) domain proteins, and other glycoproteins and lipid transporters related to those in mammals. Confocal and transmission electron microscopy revealed, with unprecedented detail, a complex and dynamic aECM. Different matrix factors assemble on the apical surfaces of each vulva cell type, with clear distinctions seen between Ras-dependent (1°) and Notch-dependent (2°) cell types. Genetic perturbations suggest that chondroitin and other aECM factors together generate a structured scaffold that both expands and constricts lumen shape.

中文翻译：

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多层动态顶端细胞外基质塑造了秀丽隐杆线虫的外阴腔

生物管必须发展并保持适当的直径才能有效地运输材料。这些管是模制的，并部分受到排列在管腔内的顶端细胞外基质 (aECM) 的保护。尽管 aECM 很重要，但它很难在体内成像，因此对其了解甚少。秀丽隐杆线虫外阴一直是理解器官发生许多方面的范例。在这里，我们描述了外阴腔基质，其中含有软骨素蛋白聚糖、透明带 (ZP) 结构域蛋白以及与哺乳动物相关的其他糖蛋白和脂质转运蛋白。共焦和透射电子显微镜以前所未有的细节揭示了复杂且动态的 aECM。不同的基质因子聚集在每种外阴细胞类型的顶端表面，Ras 依赖性 (1°) 和 Notch 依赖性 (2°) 细胞类型之间存在明显区别。遗传扰动表明软骨素和其他 aECM 因子共同产生一个结构化支架，该支架既可以扩张又可以收缩管腔形状。