Mapt isoforms in guinea pig brain.

<p><b>A)</b> Schematic diagram of the alternative splicing pattern of human <i>Mapt</i>. Six Mapt isoforms (0N3R, 1N3R, 2N3R, 0N4R, 1N4R, 2N4R) are generated from alternative splicing of exon2, 3 and 10 of the solo Mapt gene. The alternative splicing of exon2 or/and 3 (green boxes) yields <i>Mapt</i> isoforms with 0, 1 or 2 inserts of 29 amino acid residues in the N-termini; whereas, alternative splicing of exon 10 (purple) generates isoforms with either 3 or 4 tubulin-binding repeats in the C-termini. To analyse whether this splicing pattern is conserved in guinea pig, two primer pairs, GTau0F/4R and GTau10F/14R were designed, targeting the corresponding region of the human exon2/3 and tubulin-binding repeats domains respectively in guinea pig Mapt. <b>B)</b> RT-PCR <i>Mapt</i>, using primer pairs GTau10F/14R.c DNA was isolated from a brain sample from guinea pig fed normal chow diet Two bands representing 3R and 4R Mapt were detected. <b>C)</b> RT-PCR of Guinea pig <i>Mapt</i>, using primer pairs GTau0F/4R. A single band representing 1N <i>Mapt</i> was detected.