Mosaic analysis of the embryonic origin of taste buds

The embryonic origins of taste receptor cells have not been established experimentally. Although related receptor cells (e.g. hair cells of the inner ear, lateral line receptors) are known to arise from neurogenic ectoderm (e.g. neural crest or placodes), taste buds are described as arising from local epithelial cells. Also unknown is whether or not each taste bud is a clone of cells, i.e. arising from a single progenitor. To address these problems, mosaic and chimeric analyses of lingual epithelium and taste buds have been undertaken. This paper describes the theory of chimeric and mosaic cell lineage analyses, the advantages and disadvantages, and the preliminary results obtained from the examination of the taste buds and lingual epithelium of: 1) mosaic Xenopus, 2) chimeric mice and 3) X-inactivation mosaic mice.