In the post-hatch chicken retina, FGFR1 and FGFR3 are highly expressed, FGFR2 is expressed at low levels, and receptors for insulin are not expressed. RT-PCR was used to detect mRNA in the post-hatch retina and liver (positive control; a). In situ hybridization was used to detected mRNA for FGFR1 (b-d) and FGFR2 (e-g) in vertical sections of the retina (b and e), CMZ (c and f), and ciliary body (d and g). The calibration bar (50 μm) in panel e applies to b and e, the bar in f applies to c and f, and the bar in g applies to d and g. Abbreviations: ONL – outer nuclear layer, INL – inner nuclear layer, IPL – inner plexiform layer, GCL – ganglion cell layer, CMZ – circumferential marginal zone.