Plays a critical role in the assembly of axonemal dynein complex (By similarity). Plays a key role in ciliary motility (PubMed:30060180). Part of the multisubunit axonemal dynein complex formed at least of two heavy chains and a number of intermediate and light chains. Morpholino knockdown results in ciliopathy-related phenotypes, such as curved bodies, hydrocephalus, abnormal otolith, randomized left-right asymmetry, and pronephric cysts, accompanied with paralyzed pronephric cilia.