Spermidine, but not spermine, is essential for pigment pattern formation in zebrafish. - Frohnhöfer HG; Geiger-Rudolph S; Pattky M; Meixner M; Huhn C; Maischein HM; Geisler R; Gehring I; Maderspacher F; Nüsslein-Volhard C; Irion U (Biology open, 2016)