Fig. 5: Calibration data: mean methylation across probes shared between the human EPIC array and the mammalian array.

The mammalian methylation array contained 5574 probes targeting the same CpG that can also be found on the human EPIC array that was not included based on being human biomarkers. However, the mammalian array probes were engineered differently than EPIC probes so that they would more likely work across mammals. By applying both array types to calibration data, we are able to compare the calibration of the overlapping probes in mice (a, c) and rats (b, d). Upper panels (a, b) and lower panels (c, d) present the results for the mammalian array and the EPIC array, respectively. The benchmark measure (ProportionMethylated, x axis) versus the mean methylation value (y axis) across 4341 CpGs that map to mice (a, c) and 3948 CpGs that map to rats (b, d). The CpGs used to compute the mean (i) are present on the human EPIC array, (ii) present on the mammalian array, and (iii) apply to the respective species according to the mappability analysis genome coordinate file. Sample sizes: n = 20 arrays for mice (a, c) and n = 15 arrays for rats (b, d). The title reports the Pearson correlation coefficients and two-sided p-values calculated using a Student’s t-test.