The expression of parp3 during zebrafish embryogenesis, which has been partially determined by ISH, is consistent with Parp3 exerting regulatory functions at these early stages. By the end of gastrulation, parp3 is expressed at a basal level throughout the embryo with a stronger expression in the axis, while during segmentation, parp3 expression is concentrated in the notochord. By 24 hpf, parp3 expression is concentrated in the anterior/head region although not restricted to a BYL719 specific structure. By knocking down the expression of Parp3 in zebrafish embryos, we readily observed a host of developmental defects within the first 48 hrs after fertilization consistent with impaired regulatory networks at the neural plate border, a region formed at the interface of the neuroectoderm and the non-neural ectoderm in the hindbrain of early embryos. Under the influence of a specific set of transcription factors, multipotent precursor cells of the neural plate border give rise to the preplacodal ectoderm and to precursors of the neural crest cells. Subsequently, an important gene regulatory network orchestrates the formation, migration and differentiation of neural crest cells into cells of the parasympathetic nervous system, melanocytes, smooth muscle cells and craniofacial cartilage, among others. In parallel, the preplacodal ectoderm differentiates into sensory placodes from which are derived all of the cranial sensory ganglia. The SoxE family transcription factors SOX8, SOX9, SOX10 are critical neural crest specifiers and also direct proper differentiation of the preplacodal ectoderm together with DLX3 and DLX4. The identification, in our ChIP-chip screen, of these genes as PARP3 targets therefore suggested that in zebrafish, Parp3 could participate in the specification of the neural plate border, neural crest formation and/or Evofosfamide diversification by regulating the expression of these genes. Indeed, the significantly reduced expression of crestin, sox9a, dlx3b, dlx4b and neurod, the absence of inner ears, the delayed pigmentation all support key transcriptional regulatory functions for Parp3 in the neural crest and neural plate border of early zebrafish embryos. Furthermore, because the expression of sox9a is already reduced by the end of gastrulation, our results suggest that parp3 is a critical determinant in the specification of the preplacodal ectoderm into otic placodes. Of note, a previous survey of PARP3 expression, in various tissues of adult monkeys, revealed a strong PARP3 expression in neurons of terminal ganglia, already suggesting that PARP3 may contribute to the functions of neurons of the peripheral nervous system.