Delay in early development in transgenic fish expressing Dmrt1bY under control of the cytoskeletal actin promoter. A, D, G, J and M: normal wild type embryo at 16 cell stage, late blastula, 90% epiboly, late neurula and 22 somite stage corresponding to stages 6, 11, 16, 18 and 26 respectively. B, E, H, K and N: Dmrt1bY transgenic line embryo. C, F, I and L: GFP expression during early development of the Dmrt1bY transgenic line. Wild type and Dmrt1bY transgenic embryos at the same time of embryonic development were obtained in the same clutch of fertilized eggs by crossing a Dmrt1bY:GFP heterozygous parental fish to a non-transgenic fish. Scale bars: 100 μM in A to L and 50 μM in M and N.