Fig. 5. Lack of Gata2 and Gata3 expression in Phox2b^–/– mice. The expression of Gata2 and Gata3 was studied in E13.5 Phox2b^LacZ/+ and Phox2b^LacZ/LacZ mouse embryos. In the Phox2b knockout Gata2 (B) and Gata3 (D) were not detectable, by contrast to the heterozygotes (A,C). Sympathetic ganglion precursors could be detected at the dorsal aorta in both Phox2b^+/– (E) and Phox2b^–/– (F) embryos by LacZ staining.