We work on epigenetic gene regulation in mammalian development and ageing. We focus on a mechanistic and biological understanding of global epigenetic reprogramming which occurs in early embryos and in primordial germ cells to return the genome to pluripotency, erase acquired epimutations, and potentially to expose retrotransposons to be silenced. Following global erasure of epigenetic memory there is epigenetic priming in the epiblast lineage which may be uniquely associated with epigenetic and transcriptional heterogeneity, creating the potential for cell fate decision making leading up to gastrulation. In the adult organism epigenetic and transcriptional heterogeneity of tissues may change during ageing, contributing to decline of transcriptional network coherence and functional decline. We are developing new methods in single cell genomics (as part of the Sanger/EBI Single Cell Genomics Centre), particularly those in which epigenetic marks are connected with transcription networks within single cells. In collaboration with colleagues we are involved in developing new computational and modelling approaches for single cell genomics.