Fig. 9

Chromosomal localization of the mos^m188 mutation. A: Positional cloning of the locus disrupted by the mos^m188 mutation. The LG6 genomic region is drawn to depict the position of the mutation with respect to microsatellite markers (Z10183, Z15259, Z12094), STSs (BO3194R/F, fc06402), and the foxd3 gene. The distance of each marker from the mos^m188 mutation is shown as the number of recombinants in 3,134 meioses. B: The PAC clones D, E, G, and the BAC clone 148H10 contain the foxd3 gene and the mos^m188 critical interval. The PAC and BAC clones are aligned to scale and the full sequence of the BAC clone is available from NCBI (Zebrafish Genome Sequencing Project). The four genes within this area and their orientation are marked. C-F: Lateral (C) and dorsolateral (D-F) views of 18-hpf embryos stained with the foxd3 riboprobe. Foxd3 is expressed in wild-type embryos in cranial neural crest (arrow) and somites (arrowheads), while it is expressed only in somites in mos^m188 mutants (D). PAC-injected embryos show partial restoration of the foxd3 expression in the cranial region (arrow, E) or unilateral clusters of foxd3-positive cells (arrow, F). G.H: Alcian Blue preparations of 5-dpf pharyngeal skeletal elements in mos^m188 (G) and PAC-injected mos^m188 embryos (H) show well-differentiated skeletal elements of the 2nd arch (arrow) and posterior arch cartilages. Abbreviations as in Figure 1.