Figure 4

Osteoblasts differentiate in a spatiotemporal pattern similar to wild types in her9 mutants, but only weakly mineralize bone. sp7:EGFP;her9 heterozygotes were crossed to her9 heterozygotes and offspring were sorted for transgene expression. 16 live transgenic animals were labeled with Alizarin Red and imaged at 3 dpf. After imaging, animals were recovered and grown in individual wells until 6 dpf when they were labeled with Alizarin Red and imaged again. Individual animals were recovered for genotyping to identify homozygous wild types (A) and homozygous her9 mutants (B) that were imaged twice. The following structures are indicated: opercle bone (op), branchiostegal ray (br), cleithrum (cl), otoliths (ot). Arrows indicate osteoblasts prominently detected along the ventral edge of the opercle at 6 dpf. Scale bar is 50 μm.