FIGURE 4.

SAP102 splice variants are developmentally regulated. A, whole rat brain lysate was collected at various ages. The P2 fraction was isolated and resolved by 10% SDS-PAGE. Samples were immunoblotted with either pan-SAP102 antibody or with I2-specific SAP102 antibody. The experiment was repeated three times and quantified using ImageQuant LAS TL software. A representative blot is shown in A. All ages were normalized to the intensity at P2, and a ratio of SAP102(I2) to total SAP102 was determined. Data represent the means ± S.E. (*, p < 0.05, one-sample t test). B, specificity of I2-specific and common SAP102 primers was confirmed by PCR with FLAG-SAP102ΔI2 and FLAG-SAP102. C, the mRNA levels of SAP102(I2) were measured by performing real-time PCR with cDNA from mouse cortex at postnatal day 2 and 20. Samples were run in triplicate (n = 3). Data represent the means ± S.E. (*, p < 0.05, Student's t test).