Table 2. Absolute Mean Methylation by Exposure Group.
Linear mixed effect models were used to compare absolute methylation levels over time by exposure group. Age, exposure group, sex, age:exposure, and age:sex were included as terms in all models. Linear mixed models for each gene also included a paired factor to account for matched, within-individual data, as well as a random factor to account for within-litter effects. Separate models were run for each gene; beta coefficients and associated p-values for age predictor from each model are reported.
| Absolute Change in Methylation Levels by Age | |||||
|---|---|---|---|---|---|
| Gene | Paired Tail Samples (N) | PND21 % Methylation (SD) | 10 Month % Methylation (SD) | Adjusted Methylation by Age - Beta coefficient† | p-value |
| LINE-1 | 260 | 65.05 (1.35) | 63.50 (1.22) | −0.943 | 0.035 |
| IAP | 222 | 90.31 (1.37) | 88.62 (1.38) | −1.321 | 2.20E-06 |
| Igf2 | 249 | 34.39 (8.69) | 37.87 (2.87) | 3.275 | 0.112 |
| H19 | 257 | 58.87 (7.06) | 49.31 (3.01) | −10.436 | 6.22E-08 |
| Esr1 | 260 | 4.26 (1.86) | 12.09 (3.00) | 7.604 | 1.44E-12 |
BOLD = p<0.05
†
Beta coefficient for Age predictor in Linear Mixed Model.