PAM localizes to motile cilia in mammalian cells. (A) Rat ependymal cells were immunostained with antibodies to acetylated tubulin (Ac tub) and mammalian PAM linker region (JH629), C-terminal domain (CT267) or PHM domain (JH1761); red brackets on PAM model show the antigen used to generate each antibody. Punctate PAM staining was observed along the length of the cilia using all three antibodies (white brackets). Scale bars: 10 µm. (B) Left, rat tracheal epithelial cells were immunostained with antibodies to acetylated tubulin and PAM (JH629). Staining for PAM was observed at the base of the cilia and foci of staining were observed in the cilia. Right, staining was greatly reduced in the presence of blocking peptide. Scale bar: 2 µm. (C) Tracheal epithelial cells were stained simultaneously for PAM (JH629) and γ-tubulin (Gam tub), a basal body marker. (D) Spermatozoa from wild-type mice were immunostained with antibodies to acetylated tubulin and mammalian PAM (CT267). Punctate localization of PAM along the length of the axoneme (white arrows), at the tip of the tail (asterisk) and in the acrosomal vesicle (white arrowhead) was observed. Scale bar: 20 µm.