Figure 1. Physical description of the nax mutant mouse.

A–B) nax mutant and wild type sibling at P10. The nax mutant is characterized by lack of hair over the entire body and a smaller stature compared to the wild type sibling. C) Growth curve of nax mutant mice in comparison with wild type siblings showing severe growth retardation during postnatal development. D–E) Dorsal view of wild type sibling (D) and nax mutant (E) cerebella at P19. (D) The wild type cerebellum developed normally with a lobulated vermis (v; middle arrow) in the middle and hemispheres (h; arrow in each side) on each side. (E) An underdeveloped vermis is prominent in the small cerebellum of the nax mutant and the boundary between the vermis and each hemisphere is not obvious. The midbrain (m) can clearly be seen from the dorsal aspect due to the small cerebellum. Individual lobules in the vermis are indicated in Roman numerals. Scale bar: E = 1 mm (D, E).