stereocilia

Definition: Stereocilia (or stereovilli) are non-motile apical modifications of the cell, which are distinct from cilia and microvilli, but closely related to the latter.

In structure, they are longer than typical microvilli, and have more of the characteristics of the cellular membrane proper. Like microvilli, they contain actin filaments, distinguishing them from microtubule-containing cilia.

They are found in three regions of the body:

 the ductus deferens
 the epididymis
 the sensory (hair) cells of the inner ear

Some sources consider epididymal stereocilia to be a variant of microvilli , rather than their own distinct type of structure.

Pathology

 mutations in whirlin (MIM.607928) in autosomal recessive non-syndromic sensorineural deafness DFNB31 (MIM.607084)

 mutations in stereocilin (MIM.606440) in non-syndromic sensorineural deafness DFNB16 (MIM.603720)