Cover legend: This is an image of a cryosection through the eye of a juvenile transgenic zebrafish in which expression of the reporter, green fluorescent protein (GFP), is controlled by regulatory elements of the zebrafish gene gfap (glial fibrillary acidic protein). The section was also processed for immunofluorescence with antibodies against proliferating cell nuclear antigen (PCNA; magenta) and Pax6 (red) and counterstained with the nuclear dye DAPI (blue). The outer segments of photoreceptors show endogenous fluorescence in the red channel. For more information, see the article by Bernardos et al. in this issue (pages 7028–7040).