a, Immunostaining of lamin A/C and lamin B1 in oocytes, zygotes, 2-cell and 8-cell embryos and blastocysts. Scale bars, 5 μm. Levels were previously quantified by western blot in ref. 24. Experiments were repeated at least three times. b, m6ATracer signals with and without auxin. Scale bar, 20 μm. Experiments were repeated at least three times with similar results. c, PCR smears amplified from ten 2-cell embryos injected with varying amounts of mRNA encoding Dam–lamin B1 and developed in the presence or absence of auxin. Experiments were repeated at least three times with similar results. d, Development to the blastocyst in the absence or presence of auxin. e, Development to the blastocyst of zygotes injected with Dam or Dam–lamin B1 mRNA in the absence or presence of auxin. f, Dam–lamin B1 profiles on chromosome 11. Black boxes represent LAD domains. g, Hierarchical clustering of Dam–lamin B1 population (n = 3) and average single cell profiles in oocyte (n = 56), zygote (n = 19), 2-cell (n = 47) and 8-cell stage (n = 42). n = number of biologically independent samples. h, Comparison of genomic profiles obtained by DamID sequencing (this study) to previous DamID on micro-arrays. Black boxes represent LAD domains called by HMM. r = Spearman’s rho. i, Venn diagram showing overlap between LADs in embryonic stem cells, ICM and trophectoderm (TE).