[en] We planned to investigate the role of Elp3 acetyl-transferase, a member of the Elongator complex, in inner ear formation.
We first analysed the spatio-temporal pattern of Elp3 mRNA expression and showed that it was expressed in the entire early otocyst at E11.5 and persisted later in the sensory epithelium of the cochlea, in the spiral ganglion and in the vestibule.
To unravel functions of Elp3, we used conditional knock-out mice in which Elp3 gene is deleted from early otocyst (Elp3cKO). We submitted these mice to a battery of vestibular testing and found significant abnormalities. Besides, the auditory brain stem response of Elp3cKO indicated that these mice are severely deaf.
We were also able to demonstrate an increased level of apoptosis in the Elp3cKO spiral ganglion leading to a reduced number of neurons and fibers innervating the sensory cells as well as a reduced number of their synaptic ribbons. Moreover, the remaining spiral ganglion neurons extend processes showing clearly defects regarding sensory cell innervation.
In conclusion, our results clearly show a role for Elp3 both in hearing and balance. We plan to go deeper in the mechanisms involved through the identification of the proteins that are targeted for acetylation by Elp3.
Delacroix, Laurence ; Université de Liège > Département des sciences biomédicales et précliniques > Département des sciences biomédicales et précliniques
