Marsupial research reveals how mammalian embryos form

Marsupial research reveals how mammalian embryos form

Researchers at the Francis Crick Institute have revealed insight into why embryos erase a key epigenetic mark during early development, suggesting this may have evolved to help form a placenta.

Marsupial embryos lack the epigenetic reset seen in placental mammals

Nature, Published online: 14 May 2025; doi:10.1038/d41586-025-01477-2Biochemical ‘DNA methylation’ marks are found across the genome in vertebrate animals, but in the early embryos of placental mammals, such as mice and humans, they are largely erased in a ‘system reset’. Surveying DNA methylation in opossum embryos reveals that, in marsupials, such marks are retained.

Marsupial, Eutherian Embryos Show Distinct Methylation

In a groundbreaking study revealing the intricacies of mammalian embryogenesis, researchers have uncovered striking differences in DNA methylation dynamics driving X chromosome inactivation (XCI) between marsupials and eutherians. This discovery not only illuminates previously obscure epigenetic mechanisms but redefines our understanding of imprinting and dosage compensation in mammalian species, with potential far-reaching implications for gene…