Integrin signaling is inhibited in the dnβ1 mice. (a) Design of a semi-quantitative RT-PCR using two distinct sets of primers (represented as arrows) binding the extracellular domains of the endogenous (β1) and the transgenic (IL2R) β1 integrins to evaluate their relative expression levels. (b) The dnβ1 integrin (IL2R) is expressed at equal or greater levels than those for the endogenous β1 integrin (β1) in all areas of the CNS, with the highest levels present in spinal cord and optic nerve. A single experiment is shown; quantification of four sets of experiments is presented in the text. (c) Western blot analysis for P-FAK (Y397) shows that integrin downstream signaling is reduced in spinal cord and optic nerve in mutant mice (dnβ1) as compared with the levels seen in wild-type mice (Wt). Antibodies against FAK and actin were used as controls. A single experiment is shown, with quantitative results from three sets of experiments presented in the text.