Scientists are still teasing out the contributions of genetic and environmental factors to epigenetic marks on the genome. Differences in DNA methylation patterns have been linked to various disease occurrences in genetically identical twins, for example, suggesting an environmental impact. And a new study, out this week (July 15) in Genome Research, extends the influence of the environment in to the uterus by demonstrating that differences between identical twins in methylation are detectable at birth. Surprisingly, methylation patterns between some twins differ more than between unrelated individuals, also suggesting a role for random chance in the development of the epigenome.
“We already know that twins behave differently and look different, and it’s probably due to epigenetics,” said Jeffrey Craig, who led the study with Richard Saffery, both at the University of Melbourne.
Because of their identical genomes, monozygotic twins allow scientists to identify epigenetic differences that may serve as markers ...
