Allelic mRNA expression measurement in polysomes of transfected cell lines and cells with native expression of <i>NAT1</i> and <i>ABCB1</i>.

<p><b>A.</b> Effect of <i>OPRM1 118A>G</i> polymorphism on cytoplasmic mRNA expression and polysome loading; an <i>A>G</i> ratio >1 indicates reduced levels of the minor <i>G</i> allele relative to the <i>A</i> allele. Equal amounts of <i>OPRM1</i> plasmids containing <i>118A</i> and <i>G</i> were co-transfected into CHO cells. The <i>118A/G</i> allelic ratios, measured with SNaPshot, represent the mean ± s.(n = 6), *p<0.049 for monosome <i>versus</i> cytoplasmic and **0.003 for monosome <i>versus</i> polysomes, two-tailed Student’s <i>t</i>-test. These profiles are representative of results from 3 independent cultures. <b>B-C.</b> AEI measurement in polysomes of lymphoblastoid cells with native expression of <i>NAT1</i> and <i>ABCB1</i>. LCL (1 x 10⁷ cells) heterozygous for <i>*4/*10</i> were selected for polysome preparation. N-acetyltransferase 1 (NAT1) <i>*10</i> allelic mRNA increased polysomal loading (lower <i>*4/*10</i> ratios, <i>p</i><0.01, corrected for gDNA ratios (B). Ribosomal occupancy of ABCB1 (MDR1) <i>3435C>T</i> allelic mRNA. <i>ABCB1 3435C>T</i> allelic mRNA ratios (C). Reduced <i>3435C/T</i> ratios demonstrated a significant reduction of the <i>3435T</i> 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).