Epigenetic tags turn off on without changing the underlying genetic code during fertilization.
Epigenetic tags are erased from chromosomes during the first days after
however on some
genes the tags remain. These are known as genes. Identical twins result when a single embryo
splits into each embryo has the same
and the same epigenome.
Because the twins share the same environment their epigenomes are very similar at birth and through the
early years of life as the twins age their
begin to differ. Their genomes remain the same but
signals from the environment act on the twins epigenomes to
and silence different genes.
differences in physical
exposure to
and stress are examples of
environmental factors that can have an effect on the epigenome.
patterns, are very
By the time the twins are well into adulthood their epigenomes, thus gene
different making each twin