Required for cytoplasmic pre-assembly of axonemal dyneins, thereby playing a central role in motility in cilia and flagella. Involved in pre-assembly of dynein arm complexes in the cytoplasm before intraflagellar transport loads them for the ciliary compartment. Localizes in the apical cytoplasm around the gamma-tubulin-positive pericentriolar region, not in the cilia. Organ laterality defects due to altered ciliary motility. Typical randomized left-right mutant leading to situs inversus. Fishes lack directional liquid flow in Kupffer's vesicle (an organ functionally equivalent to the mouse node in terms of left-right specification). Although the number and length of cilia in Kupffer's vesicle seem normal, their motility is completely lost. Homozygous fish are viable but develop primary ciliary dyskinesia. Furthermore, male mutant fish have impaired sperm motility leading to reduced fertility. Ultrastructurally, affected cilia and flagella show partial or complete loss of outer and inner dynein arms. This loss of dynein arms is more severe in Kupffer's vesicle cilia than in sperm flagella. Belongs to the PIH1 family. Kintoun subfamily.