Mosaic analysis of the embryonic origin of taste buds

The embryonic origins of taste receptor cells have not beenestablished experimentally. Although related receptor cells(e.g. hair cells of the inner ear, lateral line receptors) areknown to arise from neurogenic ectoderm (e.g. neural crest orplacodes), taste buds are described as arising from local epithelialcells. Also unknown is whether or not each taste bud is a cloneof cells, i.e. arising from a single progenitor. To addressthese problems, mosaic and chimeric analyses of lingual epitheliumand taste buds have been undertaken. This paper describes thetheory of chimeric and mosaic cell lineage analyses, the advantagesand disadvantages, and the preliminary results obtained fromthe examination of the taste buds and lingual epithelium of:1) mosaic Xenopus, 2) chimeric mice and 3) X-inactivation mosaicmice.