Involved in smoothened signaling pathway. Acts upstream of or within several processes, including animal organ development; regionalization; and regulation of smoothened signaling pathway. Located in sperm cytoplasmic droplet; sperm midpiece; and sperm principal piece. Part of intraciliary transport particle B. Is expressed in several structures, including brain; endocrine gland; genitourinary system; olfactory epithelium; and trachea. Used to study VACTERL association; atrioventricular septal defect; and retinal degeneration. Human ortholog(s) of this gene implicated in Bardet-Biedl syndrome 20; retinitis pigmentosa 71; and short-rib thoracic dysplasia 10 with or without polydactyly. Orthologous to human IFT172 (intraflagellar transport 172). [provided by Alliance of Genome Resources, Apr 2022]