Identification and characterization of the novel planar cell polarity gene <em>Flattop</em> (<em>Fltp</em>).

To analyze the expression as well as the function of the novel planar cell polarity (PCP) gene Flattop (Fltp), we generated a knock-in/knock-out mouse. Fltp activity could be shown in mono- and multiciliated tissues depending on PCP. Inactivation of Fltp leads to defects during development of various organs which are characteristic for PCP mutants. On molecular level, Fltp assists during basal body transport and positioning