Compositions and methods are disclosed for the therapeutic use of an atonal-associated nucleic acid or amino acid sequence. Also, an animal heterozygous for an atonal-associated gene inactivation is also disclosed having at least one atonal-associated nucleic acid sequence replaced by insertion of a heterologous nucleic acid sequence used to detect expression driven by an atonal-associated promoter sequence, wherein the inactivation of the atonal-associated nucleic acid sequence prevents expression of the atonal-associated gene.