c x43 null zebrafish have reduced motile cilia in ECs. a Electropherograms of the target sequences of the cx43 gDNA in WT and cx43 −/− zebrafish. Arrow indicates the deletion of the T nucleotide. b Zebrafish ( n = 71) at 2 months post-fertilization (mpf) from mating of cx43 +/− zebrafish were genotyped for cx43 . c Images of 3 mpf zebrafish with the indicated cx43 genotype. d WT or cx43 −/− embryos at 2 dpf were immunostained with anti-acetylated-α-tubulin antibody, imaged with a confocal microscope and genotyped for cx43 . Arrowheads represent motile cilia. Dorsal view anterior to the left. Scale bar = 20 μm. e Larvae at 8 dpf from mating of cx43 +/− zebrafish were cut into cranial and caudal halves. The cranial half was used for cx43 genotyping, and the caudal half was coronally sectioned at a thickness of 14 μm and then processed for IF staining with anti-acetylated-α-tubulin antibody. Arrowheads represent motile cilia. Dorsal view anterior to the left. Scale bar = 30 μm. f Quantification of the number of cilia per frame in embryos in e . Mean ± SD. **** P