Fig. 7. Developmental changes in lacZ expression with the F5placZ construct. Lateral (A,B,D,H) and dorsal (I) views of the transgenic embryos following ß-galactosidase staining. Sagittal (C,G) and transverse (E,F) sections of the transgenic embryos. (A) 9.5, (B,C) 10.5, (D-G) 11.5 and (H,I) 13.5 dpc transgenic embryos. lacZ expression is detected in the ventral diencephalon at 9.5 dpc (arrowhead; A). At 10.5 dpc, lacZ expression is present in the ZLI (white arrowheads; B). lacZ activity occurs in the mammillary recess (arrowhead; C). At 11.5 dpc, transgene activity remains in the lateral mesencephalon, ZLI (arrowheads) and the ventral diencephalon, including in the retromammillary region (D-G). d, diencephalon; m, mesencephalon; t, telencephalon.