DNA methylation is a well-known epigenetic mark consisting in the addition of a methyl group to the cytosine producing the 5-methylcytosine (5mC). 5mC is abundant in mammalian genomes and occurs almost exclusively at CpG dinucleotides. Globally, mammalian genomes are CpG-poor but some regions, termed CpG islands, have a high CpG frequency and are found frequently in promoters. Only 2 to 4% of CpG islands are methylated in somatic cells. This process is essential to maintain stable gene repression of developmental, imprinted and X-linked genes. Several methods are available for mapping DNA methylation. Compared to the Whole Genome Bisulfite Sequencing, the Reduced Representation Bisulfite Sequencing (RRBS) allows a good coverage of gene promoters and CpG islands for a lower sequencing cost (Meissner et al. 2008). Here we describe an optimized RRBS protocol, derived from the original protocol described by (Gu et al. 2011), which allows the use of small amount of starting DNA (2ng) with good efficiency.
1- CNRS, University of Strasbourg, UMR7242 Biotechnology and Cell, signalling 300, Bd Sébastien Brant - 67412 Illkirch, France
Corresponding author: Michael Weber