Basal body docking failure triggers centriole clustering and elimination in mammalian spermatogenesis.

Cilia are microtubule-based organelles essential for signaling and motility, and their dysfunction causes ciliopathies often associated with infertility. In male germ cells, two types of cilia are present: zygotene primary cilia and sperm flagella. To define the role of cilia in spermatogenesis, we conditionally ablate the distal appendage protein CEP164, required for basal body docking and ciliogenesis, in male germ cells. CEP164 localizes to the mother centriole/basal body throughout spermatogenesis, and its loss leads to male infertility accompanied by the absence of both zygotene cilia and sperm flagella. Despite defective ciliogenesis, meiotic chromosome pairing and DNA double-strand break repair proceed normally. However, round spermatids exhibit basal body docking and flagellogenesis defects, and frequently form supernumerary centriole clusters, which appear to be subsequently eliminated via residual bodies. Live-cell imaging reveals that centrioles are highly mobile, and centriole pairs from neighboring cells are often associated, possibly through intercellular bridges, forming aggregates. These results establish that basal body docking is crucial for retaining centrioles within spermatids, and its disruption leads to centriole clustering and loss.