Quantitative analysis of the VAMP7 isoform mRNA levels in human cell lines and tissues. Color coding for all isoforms is reported; in the upper graph, 100% is the VAMP7 mRNA pool, of which the black part represents the pool of alternative isoforms (b+c+d+h+i+j) mRNA. In the middle, original data (mRNA levels of each isoform) are reported as % of the housekeeping reference gene (ribosomal S13) mRNA. Lower graphs compare individual levels within the pool of alternative isoforms (excluding VAMP7a). Cell lines (1-5) and tissues (6-10) are the followings: 1, C63; 2, HepG2; 3, HeLa; 4, Jurkat; 5, SH-SY5Y; 6, fetal brain; 7, adult brain; 8, colon; 9, skeletal muscle; 10, spleen.