Table 3

AgeCGs and nonageCGs affiliated with gene expression within tissues classified by CpG contexta
AgeCGs/genesb Non-ageCGs/genesc P-valued
Expressed Non-expressed Expressed Non-expressed
Blood
  All 271 (46.2) 315 (53.8) 4610 (78.4) 1270 (21.6) <2.2 × 10-16 *
  Island only 121 (36.1) 214 (63.9) 2251 (89.0) 277 (11.0) <2.2 × 10-16 *
  Shore only 101 (72.7) 38 (27.3) 1610 (83.5) 317 (16.5) 1.5 × 10-3 *
  Other only 49 (43.8) 63 (56.2) 749 (52.6) 676 (47.4) 0.09
Brain
  All 591 (78.8) 159 (21.2) 4404 (89.3) 528 (10.7) 3.5 × 10-16 *
  Island only 328 (79.4) 85 (20.6) 2243 (97.0) 70 (3.0) <2.2 × 10-16 *
  Shore only 184 (85.6) 31 (14.4) 1564 (95.0) 82 (5.0) 1.2 × 10-7 *
  Other only 79 (64.8) 43 (35.2) 597 (61.4) 376 (38.6) 0.53
Kidney
  All 1209 (77.4) 354 (22.6) 4046 (89.9) 456 (10.1) <2.2 × 10-16 *
  Island only 402 (71.2) 163 (28.8) 2089 (97.5) 54 (2.5) <2.2 × 10-16 *
  Shore only 440 (85.8) 73 (14.2) 1362 (95.0) 71 (5.0) 1.1 × 10-11 *
  Other onlye 367 (75.7) 118 (24.3) 595 (64.3) 331(35.7) 1.6 × 10-5 *
Muscle
  Allf 515 (77.2) 152 (22.8) 2784 (71.8) 1095 (28.2) 4.2 × 10-3
  Island only 258 (78.4) 71 (21.6) 1262 (87.3) 184 (12.7) 5.2 × 10-5 *
  Shore only 142 (86.1) 23 (13.9) 1065 (82.0) 233 (18.0) 0.24
  Other only 115 (66.5) 58 (33.5) 457 (40.3) 678 (59.7) 1.6 × 10-10 *

aExpressed genes, FPKM > 0.25; non-expressed genes, FPKM < 0.05. Parentheses indicate percentage of total in each CpG context category.

b,cGenes in proximity to an ageCG or non-ageCG according to the smallest age-associated P-value for representative genes in each tissue.

dResulting P-values from Pearson’s Chi-squared tests between numbers of ageCGs and non-ageCGs within each classification.

eAgeCGs/genes found within CGOs from kidney showed a significantly greater number of expressed genes compared to non-ageCGs in kidney.

fMuscle was the only tissue that showed a greater number of total ageCGs/genes expressed compared to non-ageCGs/genes regardless of CpG contextthis same effect was observed within the CGO category.

*Significant P-values meet Bonferroni correction for multiple testing.

Day et al.

Day et al. Genome Biology 2013 14:R102   doi:10.1186/gb-2013-14-9-r102

Open Data