Distribution of mapped mutations among the zebrafish chromosomes. Light blue, ENU mutations mapped in the present work. Purple, insertional mutations from the laboratory of N. Hopkins ( and unpublished data, available from ZFIN ), shown for comparison. Numbers for insertional mutations were obtained by searching ZFIN for mutations with a "hi" designation assigned to each linkage group and eliminating multiple hits of the same gene as well as mutations with ambiguous chromosomal assignments. Yellow, Ensembl genes predictions for each chromosome (× 100) (Ensembl release Zv6, available from Ensembl ) The number of mapped mutations or genes is indicated on the vertical axis, the linkage group (LG) number on the horizontal axis.