A sense of colour

The fluorescent honeycomb above is the sensory epithelium of the mouse auditory organ, viewed in cross-section to show the cell bodies of the sensory hair cells. The bright green sensory hair cells have been infected with a viral vector that carries the gene for the green fluorescent protein (GFP). The tissue is counterstained for actin (red), which is abundant in the hair bundles and the pericuticular necklace that rings each cell. The hair bundles are particularly clear in the vertical section of hair cells from a mouse vestibular organ shown at bottom right. A single cell transfected with the GFP gene glows green. This successful viral-mediated gene transfer into the sensory cells of the inner ear raises the possibility of gene therapy in the treatment of genetic deafness. For details, see Holt