Dna methylation measurement for mammals based on conserved loci

A method of making a DNA methylation array comprising a plurality of polynucleotides coupled to a matrix, wherein the plurality of polynucleotides:

• (a) comprise:
• a CpG motif;
• at least 2,000 unique polynucleotide sequences that hybridize to a 60 nucleotide segment in genomic polynucleotide sequences of a marsupial mammalian species, a monotreme mammalian species, a Laurasiatheria mammalian species, a Euarchontoglires mammalian species, a Xenarthra mammalian species and an Afrotheria mammalian species with less than a 3 base pair mismatch;
• and
• (b) are selected by:
• (i) performing a polynucleotide sequence alignment comparing a human genome with a plurality of non-human mammalian genomes to identify polynucleotide sequences in the human genome comprising CpG methylation sites that are homologous to polynucleotide sequences comprising CpG methylation sites within genomes of non-human mammalian species;
• (ii) ranking the polynucleotide sequences in the human genome identified in (a), wherein the ranking criteria comprises a degree of sequence homology to polynucleotide sequences in the genomes of non-human mammalian species;
• and
• (iii) using the ranking in (ii) to select a plurality of polynucleotides having CpG methylation sites that cross hybridize to a plurality of polynucleotide sequences having CpG methylation sites in the genomes of non-human mammalian species with not more than a 3 base pair mismatch;
• and
• (c) coupling selected sequences from step (b) to a matrix so as to form a DNA methylation array;
• so that the DNA methylation array is made.

A DNA methylation array comprising a plurality of polynucleotide sequences coupled to a matrix, wherein:

• the polynucleotides comprise at least 40 nucleotides and a CpG motif at their terminal ends;
• the polynucleotides comprise polynucleotide sequences present in a human genome;
• and:
• at least 2,000 polynucleotides within the plurality of polynucleotide sequences can hybridize to a 40 nucleotide segment in genomic polynucleotide sequences of a marsupial mammalian species with less than a 3 base pair mismatch;
• at least 2,000 polynucleotides within the plurality of polynucleotide sequences can hybridize to a 40 nucleotide segment in genomic polynucleotide sequences of a monotreme mammalian species with less than a 3 base pair mismatch;
• at least 2,000 polynucleotides within the plurality of polynucleotide sequences can hybridize to a 40 nucleotide segment in genomic polynucleotide sequences of a Laurasiatheria mammalian species with less than a 3 base pair mismatch;
• at least 2,000 polynucleotides within the plurality of polynucleotide sequences can hybridize to a 40 nucleotide segment in genomic polynucleotide sequences of a Euarchontoglires mammalian species with less than a 3 base pair mismatch;
• at least 2,000 polynucleotides within the plurality of polynucleotide sequences can hybridize to a 40 nucleotide segment in genomic polynucleotide sequences of a Xenarthra mammalian species with less than a 3 base pair mismatch;
• and
• at least 2,000 polynucleotides within the plurality of polynucleotide sequences can hybridize to a 40 nucleotide segment in genomic polynucleotide sequences of a Afrotheria mammalian species with less than a 3 base pair mismatch.