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Development and Evolution of the Vertebrate Ear's Neurosensory System

  1. Bernd Fritzsch,
  2. Marie-Dominique Crapon de Caprona

Published Online: 18 OCT 2010

DOI: 10.1002/9780470015902.a0020917

eLS

eLS

How to Cite

Fritzsch, B. and Crapon de Caprona, M.-D. 2010. Development and Evolution of the Vertebrate Ear's Neurosensory System. eLS. .

Author Information

  1. University of Iowa, CLAS, Iowa City, Iowa, USA

Publication History

  1. Published Online: 18 OCT 2010

Abstract

Ear development transforms an area of head ectoderm into a complex three-dimensional structure carrying three types of sensory systems for gravistatic and angular acceleration sensation as well as hearing. Transformation of the otic ectoderm starts with the specification of neurosensory cells that differentiate into the essential components for the sensory processes, the hair cells, supporting cells and neurons. The role of proneural bHLH genes in this process is presented and put into the context of ear evolution to appreciate how cellular diversity is embedded into the diversification of the ear as whole as well as the evolution of novel sensory capacities in the ear. Ear neurosensory development is characterised by extensive cross-regulation of multiple factors for cell type specification and fate fixation. Data suggesting that sensory epithelia may directly regulate the formation of their associated structures to guide specific stimuli to the sensory epithelia are presented.

Key Concepts:

  • Numerous coexpressed factors regulate transformation of general epidermis to prosensory otic ectoderm.

  • Proneural basic-Helix–Loop–Helix proteins define cell fate through cross-regulative interaction.

  • Sensory epithelia regulate formation of accessory structures including aspects of ear morphogenesis.

  • Ear development can best be understood in the context of ear evolution.

Keywords:

  • ear development;
  • neurosensory development;
  • auditory system development