Figure 5.
FOXP2 is differentially expressed in boys' versus girls' cortex. Postmortem cortex from the left hemisphere of Brodmann's area 44 from 4-year-old boys and girls were obtained from the NICHD Brain and Tissue Bank, University of Maryland, Baltimore. The relative amount of FOXP2 and FOXP1 protein was quantified by Western blot. A, Cortex from girls had significantly more FOXP2 than cortex from boys. Data are expressed as mean (±SEM), n = 5/group, significant gender difference (*p < 0.05, t test). B, In these same samples, there was no sex difference in level of FOXP1 protein. GAPDH indicates loading control. C, Regression analysis between protein levels (via Western blot) and mRNA levels for FOXP2 showed a significant positive linear relationship (r = 0.70, p = 0.02, r2 = 0.50).