Structure of the zpu.1 promoter and transient expression of EGFP. (A) Restriction map of the genomic region upstream of the first exon of zpu.1. (B) Restriction map of the zpu.1 genomic fragment and the EGFP transgene in the 9pu.1-EGFP construct used for injection to establish transgenic lines. (C) Fluorescent image of 22 hpf living embryos injected with linearized 9pu.1-GFP at the one-cell stage. The white arrowhead indicates zpu.1-expressing myeloid cells migrating from the anterolateral mesoderm over the yolk; and the yellow arrowhead, fluorescence in skeletal muscle. Lateral views, anterior is to the left, dorsal is up. Original magnification × 40.