Exons 8 and 9 were replaced with an IRES-lacZ cassette and a floxed pgk-neo cassette via homologous recombination. Cre mediated recombination removed the neo cassette. At P28 beta-galactosidase activity is detected in both type I and type II hair cells of the saccular macula, utricular macula, and cristae ampullaris. (J:184419)