In situ hybridization shows ZBED4 mRNA localized to inner segments of human photoreceptor cells in human retina. (A) Sections (8 μm thick) of fixed and cryoprotected human retina were hybridized with either antisense or sense ZBED4 digoxigenin (DIG)–labeled riboprobes. ZBED4 message localized to the inner segment of presumptive cone cells; no signal was detected with the sense probe. (B) Higher magnification of a labeled retinal section showing patchy expression of ZBED4, suggesting its expression in cone cells. OS, outer segments; IS, inner segments; ONL, outer nuclear layer; INL, inner nuclear layer; GCL, ganglion cell layer. Magnification: (A) ×200; (B) ×400.