Expression levels of Nab genes in Egr2 null mice. Sciatic nerves were isolated from Egr2 wild type (+/+) and knockout (-/-) mice. The relative levels of the Nab1 and Nab2 genes are indicated relative to the wild type sample, which was set as 1. Each level was determined from >10 pooled mice of the same genotype and normalized to the level of 18S rRNA. Quantitative PCR assays were performed in duplicate, and the standard deviation is indicated. Further analysis of nerves from individual mice at P7 (3 of each genotype) confirmed reduction of Nab1 (expression level of 0.58 for Egr2 -/- relative to 1 for wild type, P = 0.04). Expression level of Nab2 in the same samples was 0.95 relative to wild type.