Table 2.
Observed Proportion and Expected Poisson Probability of Promoters Classified into Each of the Six CpG Density Categories in the Human Genome
| Number of CpG Sites per 1,000 Bases of Promoter Sequence |
Total | ||||||
|---|---|---|---|---|---|---|---|
| 0–25 | 26–40 | 41–50 | 51–60 | 61–75 | >75 | ||
| Observed number of promoters | 10,028 | 3,306 | 2,205 | 2,674 | 4,888 | 11,056 | 34,157 |
| Observed proportion of promoters (%)a | 29.36 | 9.68 | 6.46 | 7.83 | 14.41 | 32.37 | 100 |
| Expected number of promoters | 5 | 2,272 | 14,155 | 14,493 | 3,187 | 38 | 34,157 |
| Expected proportion of promoters (%) | 0.01 | 6.65 | 41.44 | 42.43 | 9.33 | 0.11 | 100 |
| Pearson’s chi-square statistic | 861.42 | 0.01 | 0.30 | 0.28 | 0.03 | 94.61 | 956.65 |
aExpected proportion is calculated based on a Poisson distribution with mean parameter equal to 51.