The Arabian killifish, Aphanius dispar, is a small tropical teleost fish living in wide range of habitats in sea water and fresh water in the Middle East. Here, we report extraordinary fluorescent pigment cells in the Arabian killifish embryo. These cells appear brown in transmitted light, yellowish white in reflected light, and as strong fluorescence in GFP and RFP filters. TEM and confocal microscopy analyses show the fluorescence emanates from leucosome-like pigment organelles. The cells express the gene encoding GTP cyclohydrolase (gch), a marker for leucophores and xanthophore. Gene knockdown and knockout of gch using morpholino or CRISPR-Cas9 induced loss of fluorescence in these embryos, indicating a crucial role of the enzyme and the associated pterine biosynthesis pathway in the generation of the fluorescence. We concluded that these cells are a highly fluorescent subtype of leucophores and have named them as fluoroleucophores.

阿拉伯金鱼（Aphanius dispar）是一种小型的热带硬骨鱼，生活在中东的海水和淡水中，栖息地广泛。在这里，我们报道了阿拉伯金鱼鱼胚胎中非凡的荧光色素细胞。这些细胞在透射光下呈褐色，在反射光下呈淡黄白色，在GFP和RFP滤光片中表现为强荧光。透射电镜和共聚焦显微镜分析表明，荧光来自类脂质体样色素细胞器。这些细胞表达编码GTP环水解酶（gch）的基因，GTP环水解酶是白细胞和黄体细胞的标记。基因敲除和基因敲除GCH使用吗啉代或CRISPR-Cas9诱导这些胚胎中的荧光丧失，表明该酶和相关的蝶呤生物合成途径在荧光产生中的关键作用。我们得出的结论是，这些细胞是隐色团的高度荧光亚型，已将其命名为氟色隐色团。