Fig. 9

The misexpression of mitfa in the developing retina is capable of inducing foci of pigmentation.

(A) Schematic of the Tol2 transposon construct expressing EGFP and FLAG-tagged Mitfa, linked by a viral 2A peptide, from a 5×UAS promoter, and containing an alpha crystallin promoter:DsRed-Express transgene marker. (B) 72 hpf larva doubly transgenic for s1003t (retinal Gal4-VP16) and UAS:EGFP-2A-FLAG-mitfa, expressing GFP in the developing retina. (C,D) 20 micron cryosections of 28 hpf larvae examined for mitfa expression through in situ hybridization revealed mitfa expression in the developing retina and lens of a GFP expressing embryo (D) but not in an embryo lacking GFP expression (C). (E–G) cryosections of a 5 dpf s1003t; UAS:EGFP-2A-FLAG-mitfa transgenic larva, displaying foci of pigmentation (E) and GFP expression (F) in the retina. (G) Overlay demonstrating extensive overlap of GFP expression and ectopic pigmentation (white arrows). Scale bar indicates 20 micrometers in (E–G). Expression of DsRed-Express is also visible in the lens in (G).