Redundant roles of PRDM family members in zebrafish craniofacial development

Background: PRDM proteins are evolutionary conserved Zn-Finger transcription factors that share a characteristic protein domain organization. Previous studies have shown that prdm1a is required for the specification and differentiation of neural crest cells in the zebrafish. Results: Here we examine other members of this family, specifically prdm3, 5, and 16, in the differentiation of the zebrafish craniofacial skeleton. prdm3 and prdm16 are strongly expressed in the pharyngeal arches, while prdm5 is expressed specifically in the area of the forming neurocranium. Knockdown of prdm3 and prdm16 results in a reduction in the neural crest markers dlx2a and barx1and defects in both the viscerocranium and the neurocranium. The knockdown of prdm3andprdm16 in combination is additive in the neurocranium, but not in the viscerocranium. Injection of sub-optimal doses of prdm1awith prdm3 or prdm16 Morpholinos together leads to more severe phenotypes in the viscerocranium and neurocranium. prdm5 mutants have defects in the neurocranium and prdm1a and prdm5 double mutants also show more severe phenotypes. Conclusions: Overall, our data reveal that prdm3,5,and16 are involved in the zebrafish craniofacial development and that prdm1amay interact with prdm3,5, and 16 in the formation of the craniofacial skeleton in zebrafish