The magnitude of <i>trans-</i> and <i>cis-</i> variation and the number of genes within 50 kb upstream and downstream of the peak boundaries.

<p>(A) The magnitude of <i>trans</i>- and <i>cis</i>-variation as a function of the distance from chromosome ends. The average variation of OCRs within 2 kb windows was plotted for 1 kb bins. The <i>trans</i>-variations within 10 kb of the chromosome ends were significantly higher than those farther away (P<6.6×10⁻²⁵). For <i>cis</i>-variation, the P value was 5×10⁻⁴ when the t-test was used. (B) The number of genes falling within 50 kb upstream and 50 kb downstream of the peak boundaries was obtained for each OCR. This number was divided by the size of the peak for the normalized gene density. Gene-rich OCRs (top 10%) and gene-poor OCRs (lowest 5%) were compared with the other OCRs by the t-test.