Dystonin deficiency reduces taste buds and fungiform papillae in the anterior part of the tongue.

The anterior part of the tongue was examined in wild type and dystonia musculorum mice to assess the effect of dystonin loss on fungiform papillae. In the mutant mouse, the density of fungiform papillae and their taste buds was severely decreased when compared to wild type littermates (papilla, 67% reduction; taste bud, 77% reduction). The mutation also reduced the size of these papillae (17% reduction) and taste buds (29% reduction). In addition, immunohistochemical analysis demonstrated that the dystonin mutation reduced the number of PGP 9.5 and calbindin D28k-containing nerve fibers in fungiform papillae. These data together suggest that dystonin is required for the innervation and development of fungiform papillae and taste buds.