Using zinc-finger nuclease-mediated mutagenesis,we have generated mutant alleles of the zebrafish talpid3(ta3)and kif7 genes.ta3 encodes a centrosomal protein that is essential for ciliogenesis.Homozygous ta3 mutant complete embryogenesis normally,but manifest a cystic kidney phenotype during the early larval stages and die within a month of hatching.Elimination of maternally derived Ta3 activity by germline replacement resulted in embryonic lethality of ta3 homozygotes.The phenotype of such maternal and zygotic(MZta3)mutant zebrafish showed the absence of primary and motile cilia as well as aberrant Hedgehog(Hh)signalling,the latter manifest by the expanded domains of engrailed(eng)and ptc2 expression in the somites,reduction of nkx2.2 expression in the neural tube,symmetric pectoral fins,cyclopic eyes and an ectopic lens.GFP-tagged Gli2a localised to the basal bodies in the absence of the primary cilia and western blot analysis showed that Gli2a protein is aberrantly processed in MZta3 embryos.Zygotic expression of ta3 largely rescued the effects of maternal depletion,but the motile cilia of Kupffers vesicle remained aberrant,resulting in laterality defects.In contrast to ta3,homozygous kif7 mutant are viable.The MZkif7showed the expanded eng and ptc2 in somites and the increased number of Prox1+ve slowtwitch muscle cells,while the neural tube patterning is normal even when Suppressor of Fused(Sufu)are depleted.Kif7 restrains the Gli1 activity and potentiates Gli2a by promoting its dissociation from the Sufu protein at the tip of primary cilium.The absence of matenal Ta3 in kif7+/-embryos causes extopic expression of eng,suggesting the interfered Hh signaling and the synergistic effect between Kif7 and Talpid3.Our findings underline the importance of the primary cilium and Kif7 regulation for Hh signaling.