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Fig. 3
The stl64 phenotype is linked to chromosome 1 and is likely caused by a nonsense mutation in fbxw7. Dorsal views of 5 dpf zebrafish showing mbp expression by WISH using the mbp riboprobe. Normal expression in the CNS by phenotypically WT siblings (A) compared to the dramatic overexpression of mbp in the stl64 mutants (B) shows increased mbp expression in the stl64 mutants. (C) When the ratio of alleles in the mutant pool compared to the sibling pool is graphed across the whole genome for the stl64 allele, a clear spike on chromosome 1 (box) is observed for stl64. This spike indicates genomic linkage to the trait used to sort the mutant and sibling pools. (D) When viewing chromosome 1, stl64 is linked to a single region of the chromosome centered ∼24 Mb (arrow). (E) Linkage map of the stl64 allele showing the three protein-coding, homozygous, nonsynonymous SNP linked to the increased mbp expression in the CNS which was used to sort the mutant and sibling pools. The most deleterious SNP is the introduced stop codon in fbxw7.