Single-cell histone modifications are used for embryo tracing

Embryos were incubated with 0.5 g H3K27ac (for the early 2cell stage) or 0.5 g H3K27me3 (for all six developmental stages) in 100 l antibody buffer and barcoded with 3 g ml–1 PAT-T5-2 and 3 g ml–1 PAT-T7-2 in 100 l high- salt Dig-wash buffer at 4 C for 1 h. Cells were fixed in 4% PFA for 15 min, blocked in 3% normal donkey serum with 0.3% Triton X-100 in PBS for 1 h at room temperature.