A study of whirlin isoforms in the mouse vestibular system suggests potential vestibular dysfunction in DFNB31-deficient patients

Pranav Dinesh Mathur, Sarath Vijayakumar, Deepti Vashist, Sherri M. Jones, Timothy A. Jones, Jun Yang

Research output: Contribution to journalArticle

9 Scopus citations

Abstract

The DFNB31 gene plays an indispensable role in the cochlea and retina. Mutations in this gene disrupt its various isoforms and lead to non-syndromic deafness, blindness and deaf-blindness. However, the known expression of Dfnb31, the mouse ortholog of DFNB31, in vestibular organs and the potential vestibular-deficient phenotype observed in one Dfnb31 mutant mouse (Dfnb31wi/wi) suggest that DFNB31 may also be important for vestibular function. In this study, we find that full-length (FL-) and C-terminal (C-) whirlin isoforms are expressed in the vestibular organs, where their stereociliary localizations are similar to those of developing cochlear inner hair cells. No whirlin is detected in Dfnb31wi/wi vestibular organs, while only C-whirlin is expressed in Dfnb31neo/neo vestibular organs. Both FL- and C-whirlin isoforms are required for normal vestibular stereociliary growth, although they may play slightly different roles in the central and peripheral zones of the crista ampullaris. Vestibular sensory-evoked potentials demonstrate severe to profound vestibular deficits in Dfnb31neo/neo and Dfnb31wi/wi mice. Swimming and rotarod tests demonstrate that the two Dfnb31 mutants have balance problems, with Dfnb31wi/wi mice being more affected than Dfnb31neo/neo mice. Because Dfnb31wi/wi and Dfnb31neo/neo mice faithfully recapitulate hearing and vision symptoms in patients, our findings of vestibular dysfunction in these Dfnb31 mutants raise the question of whether DFNB31-deficient patients may acquire vestibular as well as hearing and vision loss.

Original languageEnglish (US)
Pages (from-to)7017-7030
Number of pages14
JournalHuman Molecular Genetics
Volume24
Issue number24
DOIs
Publication statusPublished - Jan 1 2015

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ASJC Scopus subject areas

  • Molecular Biology
  • Genetics
  • Genetics(clinical)

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