Table 2.
Median methylation changes as a function of aging (young – old individuals) in epigenetic clock CpGs relative to CpG islands, transcription start and tentative splice sites. Correlation to the presence of G4, tentative splice sites and characteristics of corresponding nascent RNA products.
| Median methylation decrease by CpG x102 (Sequences) | Median methylation increase by CpG x102 (Sequences) | p-value* | G4 (Frequency) |
Total sequences | Median ΔG | Ps+ or Amb+ (Frequency) | Total Splice sites (Frequency per sequence) |
|
|---|---|---|---|---|---|---|---|---|
| CpG island | 2.034 (34) |
2.965 (91) |
0.195 | - | 135 | - | - | 189 (1.400) |
| CpG island G4+ | 3.122 (17) |
3.147 (58) |
0.982 | - | 75 | 25.53 | 28 (0.373) |
101 (1.347) |
| CpG island G4- | 0.947 (17) |
2.890 (40) |
0.041 | - | 60 | 20.69 | 33 (0.55) |
88 (1.467) |
| Open Sea | 6.256 (31) |
2.644 (25) |
0.005 | 16 (0.246) |
65 | 17.90 | 37 (0.569) |
95 (1.462) |
| TSS1500 | 4.168 (41) |
2.968 (41) |
0.191 | - | 89 | - | - | 133 (1.494) |
| TSS1500 G4+ | 2.64 (10) |
3.845 (17) |
0.434 | - | 28 | 22.99 | 17 (0.643) |
37 (1.321) |
| TSS1500 G4- | 4.661 (31) |
2.346 (24) |
0.048 | - | 61 | 17.50 | 44 (0.685) |
96 (1.574) |
| TSS200 only | 3.553 (15) |
2.963 (19) |
0.665 | 14 (0.333) |
42 | 20.12 | 29 (0.69) |
32 (0.762) |
| Including 5’ UTRs | 3.946 (41) |
2.251 (45) |
0.046 | 41 (0.461) |
89 | 20.83 | 47 (0.528) |
136 (1.528) |
| Sequences without tentative splice sites | 3.819 (42) |
2.952 (36) |
0.456 | 25 (0.291) |
86 | 17.58 | 52 (0.604) |
0 |
| Sequences with tentative splice sites | 4.314 (106) |
2.872 (141) |
0.008 | 109 (0.405) |
269 | 20.94 | 154 (0.572) |
510 (1.896) |
| Hypothetical proteins | 2.359 (22) |
2.718 (27) |
0.70 | 21 (0.396) |
53 | 21.00 | 28 (0.528) |
55 (1.038) |
*Student’s t-test