In some aspects, described herein is a DNA methylation reporter. In some aspects, the DNA methylation reporter comprises a promoter whose activity can be affected by exogenous methylation changes without being independently regulated by the DNA methylation machinery, operably linked to a DNA sequence that encodes a reporter molecule. In some embodiments the DNA methylation reporter comprises (i) a promoter derived from a mammalian imprinted gene promoter； and (ii) a sequence that encodes a reporter molecule that is detectable in individual mammalian cells, wherein the promoter is operably linked to the sequence that encodes the reporter molecule. Also described are nucleic acids that comprise the DNA methylation reporter, cells that have the DNA methylation reporter integrated into their genome, and non-human mammals comprising cells that have the DNA methylation reporter integrated into their genome. Also described are methods of measuring DNA methylation of a region of interest located in proximity to the DNA methylation reporter in the genome of a cell by detecting the reporter molecule.
