Over recent decades, scientists have made various discoveries about DNA methylation and how vital it is to a number of cellular processes such as embryonic development, X-chromosome inactivation, genomic imprinting, gene suppression, carcinogenesis and chromosome stability. Researchers have linked abnormal DNA methylation to several adverse outcomes, including human diseases.
Aneuploidy-the incorrect number of chromosomes in a cell-is extremely common in early embryos and is the primary reason for pregnancy loss. A report published today (April 9) in Science reveals that one cause of this aneuploidy-aberrant cell divisions in the embryo-is linked to a genetic mutation carried by the mother. Astonishingly, this mutation turns out to be very common and appears to have been under positive selection during human evolution.