A versatile fluorescent probe for imaging fibrillar collagen during avian morphogenesis

Fibrillar collagen architecture provides a fundamental structural framework for vertebrate tissues. Understanding how collagen matrices are organized and remodeled requires high-resolution imaging approaches capable of resolving their three-dimensional architecture and developmental dynamics in vivo. We previously established that the fluorescent probe DAF FM DA enables sensitive visualization of collagen structures in zebrafish, amphibian, and mouse tissues. However, whether this approach is applicable to avian embryos - an important model system in morphogenesis research - has remained unclear. Here we demonstrate that DAF FM DA specifically and robustly labels collagen matrices in quail embryonic tissues. Using this method, lattice like stromal networks in the cornea and spongy matrices in the limb cartilage primordium were clearly visualized throughout deep tissue regions. This imaging strategy provides a practical and versatile tool for investigating collagen matrix development in vertebrate morphogenesis using avian embryos.