Fig 2. Allelic mRNA expression measurement in polysomes of transfected cell lines and cells with native expression of NAT1 and ABCB1.

A. Effect of OPRM1 118A>G polymorphism on cytoplasmic mRNA expression and polysome loading; an A>G ratio >1 indicates reduced levels of the minor G allele relative to the A allele. Equal amounts of OPRM1 plasmids containing 118A and G were co-transfected into CHO cells. The 118A/G allelic ratios, measured with SNaPshot, represent the mean ± s.(n = 6), *p<0.049 for monosome versus cytoplasmic and **0.003 for monosome versus polysomes, two-tailed Student’s t-test. These profiles are representative of results from 3 independent cultures. B-C. AEI measurement in polysomes of lymphoblastoid cells with native expression of NAT1 and ABCB1. LCL (1 x 10⁷ cells) heterozygous for *4/*10 were selected for polysome preparation. N-acetyltransferase 1 (NAT1) *10 allelic mRNA increased polysomal loading (lower *4/*10 ratios, p<0.01, corrected for gDNA ratios (B). Ribosomal occupancy of ABCB1 (MDR1) 3435C>T allelic mRNA. ABCB1 3435C>T allelic mRNA ratios (C). Reduced 3435C/T ratios demonstrated a significant reduction of the 3435T allele in the cytoplasmic mRNA extract, with no significant difference in any gradient fraction. These profiles are representative of gradients done with extracts from 3 independent cultures (mean ± s.d., n = 6).