Fig. 4. Mosaic expression of a dominant-negative fragment of Shroom2 disrupts eye pigmentation. (A) Lipofection enables mosaic expression of dominant-negative Shroom2 specifically in the Xenopus eye. Constructs are lipofected into the eye field at stage 18 and grown to stage 42. All constructs are mixed at a ratio of 1 µg plasmid/3 µl DOTAP and pulsed in 10 nl volumes. (B,b') Lipofection of membrane GFP alone results in normal eye morphology and pigmentation (melanin in the RPE obscures GFP fluorescence in b'). (C,c') Embryos lipofected with membrane GFP and Shroom2(576-882) showed patchy hypopigmentation in areas where GFP was localized.