Updated project metadata. Here we investigate the possible relationship between the propagation of epigenetic information and the developmental cell proliferation during Xenopus embryogenesis. We systemically inhibited cell proliferation during the G1/S-transition in gastrula embryos and followed their development until the tadpole stage. We quantified by mass spectrometry the abundance of a large set of histone modification states, which reflects the developmental maturation of the embryonic epigenome.