Characterization of zebrafish gcsf. (A) Synteny analysis of human GCSF and zebrafish gcsf gene loci. Pentagons represent genes showing their respective orientations: white indicates GCSF/gcsf genes; black, genes showing conserved synteny; and gray, nonsyntenic genes. (B) Alignment of human, mouse, and zebrafish GCSF sequences, as described in Figure 1. Predicted α-helical secondary structure is indicated for mammalian (black helices) and zebrafish (gray helices) sequences. Exons are indicated by alternating gray and white shading. (C) Phylogenetic analysis of GCSF and related cytokines from human (hs), mouse (mm), pig (ss), chicken (gg), cat (fc), fugu (tr), pufferfish (tn), and Japanese flounder (po) using the neighborhood-joining algorithm. Branches with a bootstrap value higher than 80% are bolded. GCSF sequences are highlighted by gray shading.