The Role of Eya Genes in Early Mammalian Ear Morphogenesis

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Distinct organs in the body of human are formed by similar signals through

cell-cell communications. This proposal focuses on the genetic details

that tell cells to form the ear and where to form. The mammalian ear

formation involves a series of different signals from different adjacent

tissues. However, despite much speculation as to the signals from

neighboring tissues, the identity of the signals and how the cells

communicate with each other are not known. A gene called Eyes absent 1 has

been knocked out in mice. Mutations in the same gene in fruit flies cause

no eye formation. Interestingly, Eya1 mutant mice develop no ears and the

cells normally forming the ear die from very early embryonic stages,

indicating that Eya1 is a key early gene required for ear development.

This proposal will use Eya1- and other Eya-deficient mice to study how the

mammalian ears form in appropriate places in the body by molecular and

genetic approaches.

This project begins to dissect out the molecular and genetic

information required for normal formation of the mammalian ear. Thus, the

major significance of the proposed studies is that they represent one of

the first attempts to define specific gene function in the context of the

normal developmental mechanisms operating in ear formation.