Figure 2. Differential expression of NGC mRNA isoforms in the adult mouse eye. A: Schematic representation of mouse NGC isoforms. Exons are numbered above the scheme. The NGC-I isoform contains exon 1 (light gray), that is replaced through alternative splicing by exon 1’ (dark gray) in the NGC-II isoform. An additional exon 5 (black) is present in isoform NGC-III. B:NGC isoform mRNA expression in adult mouse tissues. RT–PCR experiments were performed on pooled tissues from four different eyes of 8-week-old mice. One representative experiment out of two is shown. RL8 mRNA expression was used as an internal standard. Abbreviations: retinal pigment epithelium with attached choroid (RPE,C); no template (-RT); 200 ng mouse genomic DNA (gen); DNA molecular weight marker X (MW). Only relevant band sizes are indicated. Specific cDNA amplification yielded products of 452 bp for NGC-I, 595 bp for NGC-II, 178 bp for NGC-III, 226 bp for IMPG2, 250 bp for CD44, and 199 bp for RL8. Amplification on genomic DNA yielded products of 595 bp for NGC-II, 1192 bp for IMPG2, and 336 bp for RL8.