title: Expression and function of Sox21 during mouse cochlea development.
abstract: The development of the inner ear is an orchestrated process of morphogenesis with spatiotemporally controlled generations of individual cell types. Recent studies have revealed that the Sox gene family, a family of evolutionarily conserved HMG-type transcriptional factors, is differentially expressed in each cell type of the mammalian inner ear and plays critical roles in cell-fate determination during development. In this study, we examined the expression pattern of Sox21 in the developing and adult murine cochlea. Sox21 was expressed throughout the sensory epithelium in the early otocyst stage but became restricted to supporting cells during adulthood. Interestingly, the expression in adults was restricted to the inner phalangeal, inner border, and Deiters' cells: all of these cells are in direct contact with hair cells. Evaluations of the auditory brainstem-response revealed that Sox21(-/-) mice suffered mild hearing impairments, with an increase in hair cells that miss their appropriate planar cell polarity. Taken together with the previously reported critical roles of SoxB1 families in the morphogenesis of inner ear sensory and neuronal cells, our results suggest that Sox21, a counteracting partner of the SoxB1 family, controls fine-tuned cell fate decisions. Also, the characteristic expression pattern may be useful for labelling a particular subset of supporting cells.
authors.affiliation: Department of Physiology, School of Medicine, Keio University, Tokyo, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Hosoya
authors.forename: Masato
authors.initials: M
authors.lastname: Fujioka
authors.forename: Satoru
authors.initials: S
authors.lastname: Matsuda
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Ohba
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Shibata
authors.forename: Fumiko
authors.initials: F
authors.lastname: Nakagawa
authors.forename: Takahisa
authors.initials: T
authors.lastname: Watabe
authors.forename: Ken-ichiro
authors.initials: K
authors.lastname: Wakabayashi
authors.forename: Yumiko
authors.initials: Y
authors.lastname: Saga
authors.forename: Kaoru
authors.initials: K
authors.lastname: Ogawa
authors.forename: Hirotaka James
authors.initials: HJ
authors.lastname: Okano
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Okano
mesh_terms: D000818:Animals; D003051:Cochlea / Q000254:growth & development*; D006199:Hair Cells, Auditory, Inner / Q000502:physiology; D051379:Mice; D055749:SOXB2 Transcription Factors / Q000096:biosynthesis* / Q000172:deficiency / Q000502:physiology*
chemical_list: D055749:SOXB2 Transcription Factors; C484489:Sox21 protein, mouse