Fig. 2. Lmx1b deletion results in a marked reduction in the size of the tectum and cerebellum. (A,B) Dorsal view of the mid/hindbrain region of P0 mouse brains. The medial portion of the cerebellum (Cb) was missing, and the remaining part of the cerebellum and the tectum were much smaller in the Lmx1b^-/- brain (B) as compared with the wild-type control (A). (C,D) Parasagittal Nissl-stained sections of P0 brains. The inferior colliculus (IC) was missing and the reduced cerebellum fused with the superior colliculus (SC) in the Lmx1b^-/- brain. (E,F) Double immunostaining of the brain sections for BRN3b (marking IC and laminated SC) and for calbindin (marking Purkinje cells in the cerebellum). cp, choroids plexus; Hy, hypothalamus; PT, pretectal region; Th, thalamus. Scale bars: 700 µm.