GFP expression of construct 3 in the gonads. Bright field (i) and fluorescence (ii) images are shown. Panel A shows fluorescence image only. (A) E11.5 dissected AGM. Only the gonadal ridges are fluorescent. (B-C) E13.5 female and male gonads with the adjacent mesonephros. Note the absence of staining of the mesonephros. Note that qualitatively similar results are obtained with constructs 1 and 2; g indicates gonad, and m indicates mesonephros. Original magnifications are × 40 (A) and × 20 (B-C).