English: Ciliary motion in reciliated mouse airway epithelia from wildtype vs. heterozygous Dnai1 knockout mice after Dnah6 siRNA knockdown. In wildtype tracheal epithelial cells, 30nM siRNA knockdown had no effect on ciliogenesis or cilia motility, as the respiratory epithelia continued to show high ciliation density and normal ciliary motion. However, with 50nM knockdown, cilia density was significantly reduced with many areas entirely devoid of cilia, and ciliary motion was abnormal and dyskinetic. In comparison, heterozygous Dnai1 knockout mouse tracheal epithelia was much more sensitive to the effects of Dnah6 siRNA knockdown. Knockdown at 30nM Dnah6, which had no effect on wildtype tracheal epithelia, caused reduced cilia density and a spectrum of ciliary motion defects ranging from immotile to restricted dyskinetic ciliary motion in heterozygous Dnai1 knockout mouse tracheal epithelia. These are similar to the phenotypes observed with 50nM Dnah6 siRNA knockdown in the wildtype tracheal epithelia. This contrasts with the completely immotile cilia observed in the tracheal epithelia of homozygous Dnai1 knockout mice. Movie was originally captured at 200 fps, and movie playback is set at 30 fps for ease of visualization (ie. 15% real time). Scale Bar = 10 μm