Figure 4.

Major morphological alterations of the met/mesencephalon in the Pax-2/Pax-5 compound mutant. Sagittal sections of wild-type (A and C) and compound Pax-2/Pax-5 (B and D) e14 embryos stained with cresyl violet (Nissl; A and B) and with radioactive probe for Engrailed-1 (in situ hybridization; C and D). The compound Pax-2/Pax-5 mutant shows loss of the midbrain tectum and of part of the midbrain tegmentum, and complete loss of the cerebellar anlage. The results of the morphological analysis are confirmed by in situ hybridization by using the En-1 probe as a marker for the cerebellum and the caudal part of the tectum and the midbrain tegmentum. 4v, fourth ventricle; CB, cerebellum; chp, choroid plexus; DOR, dorsal thalamus; is, isthmus; MY, medulla; P, pons; PRTp, precommissural pretectum; tc, midbrain tectum; tg, midbrain tegmentum; TL, telencephalon.