Loss and gain of function of prdm1a results in craniofacial defects. A: 48 hpf prdm1a-GFP embryo stained with zn8 antibody showing the normal structure of the pharyngeal endodermal pouches. B: A prdm1a mutant (in a tg{prdm1a::GFP} background) stained with anti-zn8 shows defects in endodermal pouch patterning. C: A 6-dpf wild type larvae stained with alcian blue to detect cartilage. D: As compared to control, the prdm1a mutant larva has a slightly inverted ceratohyal (ch) and is missing the cartilages of pharyngeal arches 4-7. E: Control 7-dpf zebrafish stained with alcian blue (cartilage) and alizarin red (endochondral and dermal bone). F: As compared to control, the prdm1a mutant larva is missing a majority of the dermal bones, as well as the 5th ceratobranchial and pharyngeal teeth, but the cleithrum is present. The otoliths in the ear are also slightly smaller. The inverted ceratohyal is outlined in white. Staining was performed at multiple timepoints and did not reflect any developmental delay in prdm1a mutants. Overexpression of prdm1a-RNA results in malformed cartilages, including (G) ectopic cartilage extending from Meckel′s cartilage (arrow). H: In addition, a fusion of the pterygoid process with a disarrayed neurocranium is observed. A,B: Lateral views, anterior to the left; C-H: ventral views, anterior is to the left. br, branchiostegal ray; cb1-5, ceratobranchial 1-5; ch, ceratohyal; cl, cleithrum; ep, ethmoid plate; M, Meckel′s cartilage; nc, notochord; op, opercle; ot, otoliths; ov, otic vesicle; pq, palatoquadrate; pt, pharyngeal teeth; tr, trabeculae. 1-6 indicate endodemal pouches; wt/het, wildtype/heterozygotes embryo.
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