Table 3.
Expression polymorphism on the X chromosome and autosomes
| X chromosome | Autosomes | X/A ratio* | |
|---|---|---|---|
| Number and percentage of polymorphic probes | |||
| Overall | 335 (35.8%) | 1,559 (37.9%) | 0.945 (P = 0.22) |
| Europe | 155 (16.5%) | 809 (19.7%) | 0.838 (P = 0.027) |
| Africa | 168 (17.9%) | 871 (21.2%) | 0.844 (P = 0.025) |
| Between | 277 (29.6%) | 1,323 (32.2%) | 0.919 (P = 0.12) |
| Average percentage of pairwise differences | |||
| Overall | 2.02 | 2.90 | 0.697 (P = 0.040) |
| Europe | 1.77 | 2.68 | 0.661 (P = 0.014) |
| Africa | 1.86 | 2.64 | 0.705 (P = 0.017) |
| Between | 2.20 | 3.11 | 0.708 (P = 0.035) |
*Deviations from 1:1 expectations for the X/A ratios were tested with two-tailed Fisher's exact tests for the percentage of polymorphic genes and with Mann-Whitney U tests for the average number of pairwise differences.