DNA METHYLATION MEASUREMENT FOR MAMMALS BASED ON CONSERVED LOCI

摘要

While methylation chips have 5 been widely used in human studies over the last ten years, methylation chips for non-human species have not, perhaps due to lack of sufficient demand and/or because species specific methylation chips may be suboptimal for cross-species comparisons. To address challenges in this technology, we developed an algorithm, Conserved Methylation Array Probe Selector (CMAPS), 10 which repurposes the degenerate base technology used to tolerate within-human variation to tolerate cross-species mutations. CMAPS performs a greedy search to obtain a maximal number of species that can be targeted using a probe for any CpG in the human genome, based on a multiple sequence alignment. CMAPS then ranks all the probes and chooses a final set so that arrays can be made that can query a large 15 number of mammalian species and varied genomic positions based on external annotations of exons, CpG islands and hyper versus hypo methylated regions.