Fig. 1. Characterization of the embryonic phenotype in mot/cha. (A) Whole-mount o-dianisidine staining of wild-type and mot/cha embryos; (top) at 48 hpf, wild-type and mot embryos have a similar number of blood cells; (middle) at 96 hpf, mot embryos lack circulating blood cells (arrow); (bottom) wild-type and cha embryos at 72 hpf are stained with o-dianisidine for hemoglobin in the cardiac sinus (arrows). (B) After the onset of anemia, excretion of bile pigments in mot embryos is noticeable (arrow) and continues for several days. (C) Wright-Giemsa staining of circulating red cells collected at 48 hpf from wild-type and mot embryos reveals the presence of cells with abnormal morphology in the mot embryos. Wild-type cells are spherical with round, open nuclei, but mot contains binucleated cells (arrow), and morphologically abnormal cells with condensed nuclei and spiculated membranes. (D) Whole-mount RNA in situ analysis of wild-type and mot embryos with the hematopoietic genes, scl, gata1 and globin reveals comparable levels of transcript expression in wild-type and mot embryos at 24 hpf, indicating that erythropoiesis in mot fish is not interrupted. Lateral views are illustrated with anterior towards the left and dorsal towards the top.