Plays a role in cytoplasmic pre-assembly of axonemal dynein. Interacts with HSPA1A/B, HSP90AA1 and DNAI2 (PubMed:24421334). Interacts with DNAAF2 and DNAAF4 (By similarity). Localized to the cytoplasm of spermatogenic cells. Specifically expressed in testis. Detected in pachytene spermatocytes from 5 weeks of age and in pachytene and diplotene spermatocytes of adult mice. Not detected in spermatids or mature sperm. Deficient mice develop normally but manifest male sterility. Sperm are immotile and fragile with the axoneme of the flagellum lacking outer dynein arms (ODAs) and inner dynein arms (IDAs) and showing a disturbed microtubules organization. Belongs to the PIH1 family.