Fig. 5. Chick Cer regulatory regions are able to drive EGFP expression in the left lateral plate mesoderm of mouse embryos. (A,B) E8.5 Cer2.5-EGFP transgenic mouse embryos in ventral (A) and left-side (B) views. (Aa) Transverse section of embryo in A (line). (Bb) Longitudinal section of embryo in B (line). Cell nuclei are labeled with DAPI (blue). Green fluorescence was asymmetrically detected in the left lateral plate mesoderm (llpm; A,B), both in the splanchnopleure and in the somatopleure (Aa,Bb). Fluorescent cells were also found in the foregut (f) and heart (h; B,Aa). (C-D') Expression patterns of EGFP (purple) and Nodal (orange; C,C') or Lefty1,2 (orange; D,D') in E8.25 transgenic mouse embryos detected by double whole-mount in situ hybridization. (C,D) Anterior views. (C',D') Left-side views. The expression domain of EGFP overlapped with Nodal and Lefty2 in the left lateral plate mesoderm. A, anterior; f, foregut; h, heart; L, left; llpm, left lateral plate mesoderm; P, posterior; R, right.