CELLULAR COMMITMENT AND DIFFERENTIATION IN THE COCHLEA - POTENTIAL ADVANCES USING GENE-TRANSFER

The development of individual cells as hair cells and supporting cells is a key step during the embryonic formation of the auditory system. However, at present the factors that play a role in the commitment and differentiation of cells as hair cells and supporting cells have not been identified. Recent advances in molecular biological techniques ha ve led to the identification of candidate genes that may be involved i n hair cell and supporting cell development, however it has been diffi cult to determine the specific effects of these genes. The development of new methods for gene transfer into post-mitotic cells should provi de powerful new techniques for examining the specific effects of candi date genes. Virally mediated vectors, such as adenovirus and herpes si mplex virus, and non-virally mediated vectors, such as lipofectins and biolistics, have been shown to efficiently transfer candidate genes i nto many different cell types, including hair cells, supporting cells, and spiral ganglion neurons. In addition, studies in other developing systems have demonstrated that these techniques can be used to determ ine the effects of expression of candidate genes during the specificat ion of individual cell phenotypes. These results suggest that these ve ctors can be used effectively to study the role of specific genes duri ng the development of the auditory system.