Developmental expression of the TGF beta s in the mouse cochlea

Mice with targeted disruption of the TGF beta 2 gene display defects in epi thelial-mesenchymal tissue interactions in several tissues including the de veloping cochlea. Specifically, the region of the spiral limbus and the ove rlying interdental cells, structures putatively involved in endolymphatic f luid homeostasis, display morphogenetic abnormalities. These findings promp ted us to explore the pre-natal and post-natal expression of all three mamm alian TGF beta genes in the developing mouse inner ear. TGF beta 2 mRNA exp ression was identified throughout the cochlear epithelium at all of the dev elopmental stages examined. TGF beta 3 mRNA expression was identified in th e mesenchymal tissues of the cochlea surrounding the otic epithelium. We fo und no evidence for compensation by the other two TGF beta isoforms in the cochleas of the TGF beta 2 mutants. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved.