Whole-organism 3D quantitative characterization of zebrafish melanin by silver deposition micro-CT

Melanin-rich zebrafish melanophores are used to study pigment development, human skin color, and as a large-scale screening phenotype. To facilitate more detailed whole-body, computational analyses of melanin content and morphology, we have combined X-ray microtomography (micro-CT), a non-destructive, full-volume imaging modality, with a novel application of ionic silver staining to characterize melanin distribution in whole zebrafish larvae. Normalized micro-CT reconstructions of silver-stained fish consistently reproduced pigment patterns seen by light microscopy, and allowed direct quantitative comparisons of melanin content across wild-type and mutant samples, for both dramatic and subtle phenotypes not previously described. Silver staining of melanin for micro-CT provides proof-of-principle for whole-body, three-dimensional computational phenomic analysis of a particular cell type at cellular resolution, with potential applications in other model organisms and human melanoma biopsi...富含黑色素的斑马鱼黑素细胞（melanin-rich zebrafish melanophores）被广泛应用于色素发育、人类肤色相关研究，并可作为大规模筛选的表型模型。为实现对黑色素含量与形态更精细的全机体计算分析，本研究将非破坏性全容积成像技术——X射线显微计算机断层扫描（X-ray microtomography，micro-CT），与离子银染色的全新应用相结合，用以表征完整斑马鱼幼虫体内的黑色素分布情况。经银染处理的斑马鱼的标准化micro-CT重建结果，可稳定复现光学显微镜下观察到的色素模式，且能够针对此前未被报道的显著与细微表型，直接开展野生型与突变体样本间的黑色素含量定量对比分析。针对micro-CT的黑色素银染技术，为以细胞分辨率对特定细胞类型开展全机体三维计算表型组学分析提供了原理验证，其潜在应用场景可拓展至其他模式生物与人类黑色素瘤活检样本……