Figure 7. Mapt isoforms in guinea pig brain.
A) Schematic diagram of the alternative splicing pattern of human Mapt. 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 Mapt 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) RT-PCR Mapt, 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. C) RT-PCR of Guinea pig Mapt, using primer pairs GTau0F/4R. A single band representing 1N Mapt was detected.