Int. J. Dev. Biol. 51: 495 - 506 (2007)
doi: 10.1387/ijdb.072345ss
© UBC Press

Hindbrain signals in otic regionalization: walk on the wild side

Sylvie Schneider-Maunoury1,2 and Cristina Pujades3,4,*

1Laboratory of Developmental Biology, CNRS, 2Université Pierre et Marie Curie, Paris, France, 3Developmental Biology Group, Departament de Ciències Experimentals i de la Salut, Universitat Pompeu Fabra and 4Parc de Recerca Biomèdica de Barcelona PRBB, Barcelona, Spain

ABSTRACT The inner ear, the sensory organ responsible for hearing and balance, contains specialized sensory and non-sensory epithelia arranged in a highly complex three-dimensional structure. To achieve this level of complexity, a tight coordination between morphogenesis and cell fate specification is essential during otic development. Tissues surrounding the otic primordium and more particularly the adjacent segmented hindbrain, have been implicated in conferring signals required for inner ear development. In this review, we present the current view on the role of hindbrain signals in axial specification of the inner ear. The functional analysis of mutants of hindbrain segmentation genes, as well as the investigation of signaling pathways potentially involved, all point to an essential role of FGF, Wnt and Hh signaling in otic regionalization. However, these data provide conflicting evidence regarding the involvement of hindbrain signals in otic regionalization in fish and in amniotes. We discuss the possible origin of these differences.

Keywords:

hindbrain, patterning, otic regionalization, FGF signaling

*Corresponding author e-mail: cristina.pujades@upf.edu