Cilia- and flagella-associated protein 251; Involved in spermatozoa motility. May also regulate cilium motility through its role in the assembly of the axonemal radial spokes (By similarity).

Cilia- and flagella-associated protein 69; Cilium- and flagellum-associated protein. In the olfactory epithelium, regulates the speed of activation and termination of the odor response and thus contributes to the robustness of olfactory transduction pathways (By similarity). Required for sperm flagellum assembly and stability.

Glutamine-rich protein 2; Has an essential role in the formation of sperm flagella and flagellar structure maintainance. It acts as a suppressor of ubiquitination and degradation of proteins involved in flagellar development and motility.

Dynein heavy chain 1, axonemal; Force generating protein of cilia required for sperm flagellum motility. Produces force towards the minus ends of microtubules. Dynein has ATPase activity; the force-producing power stroke is thought to occur on release of ADP. Required in spermatozoa for the formation of the inner dynein arms and biogenesis of the axoneme ; Belongs to the dynein heavy chain family.

Cilia and flagella associated protein 70; Belongs to the CFAP70 family.

Cilia- and flagella-associated protein 91; May play a role in spermatogenesis. May regulate cilium motility through its role in the assembly of the axonemal radial spokes (By similarity).

Coiled-coil domain-containing protein 39; Required for assembly of dynein regulatory complex (DRC) and inner dynein arm (IDA) complexes, which are responsible for ciliary beat regulation, thereby playing a central role in motility in cilia and flagella. Probably acts together with CCDC40 to form a molecular ruler that determines the 96 nanometer (nm) repeat length and arrangements of components in cilia and flagella (By similarity). Not required for outer dynein arm complexes assembly ; Belongs to the CCDC39 family.

Tetratricopeptide repeat protein 21A; Intraflagellar transport (IFT)-associated protein required for spermatogenesis. Required for sperm flagellar formation and intraflagellar transport. Belongs to the TTC21 family.

Sperm flagellar protein 2; Required for correct axoneme development in spermatozoa. Important for normal development of the manchette and sperm head morphology. Essential for male fertility. Plays a role in localization of the intraflagellar transport protein IFT20 to the manchette, suggesting function as an adapter for dynein-mediated protein transport during spermatogenesis. Also plays a role in bone growth where it seems to be required for normal osteoblast differentiation.