Figure 1.

The germline Nf1 gene mutation determines the level of neurofibromin expression. (A) Schematic illustration of the mouse Nf1 gene, with the alternate exons and RAS-GAP domain indicated. The positions of the three germline Nf1 gene mutations are depicted above exons 18, 21 and 31. (B) Neurofibromin expression was reduced in the brainstem of mice with Cre-mediated Nf1^flox inactivation and G848R^CKO and R681X^CKO or null KO (neo^CKO) alleles by 38, 77 and 47%, respectively, relative to control mice following normalization to α-tubulin. (C) The effect of these germline Nf1 gene mutations on neurofibromin expression was examined in the optic nerve by immunohistochemistry. At least three mice were used per genotype.