Characterization of L1 at 13q14.2. (a) Diagram of L1 at 13q14.2 and the surrounding region. The arrow designates the L1 transcript. Triangles at F and R indicate positions of oligonucleotides 13q14.2F and 13q14.2R. Blue boxes indicate exons of the RB1 gene, with exon number designated. Oligonucleotides RB1-1 and RB1-2 are indicated. The sequence of the 3' expression tag is provided. (b) Relative expression of the L1 at 13q14.2 in lymphoblastoid cell lines from CEPH individuals. Expression is in arbitrary units normalized to HPRT1. Error bars indicate ± standard deviation from three replicates. (c) Expression of CEPH individuals of the L1 at 13q14.2 compared to flanking exons from RB1, normalized to HPRT1. Expression is plotted on a logarithmic scale so that levels for both amplicons can be clearly visualized. Error bars represent ± standard deviations from three replicates. All data are representative of at least two biological replicates.