Epigenetics Animation

Uploaded by NCINews on 14.06.2010

Epigenetics is the study of inherited changes
in gene function that occur without a change
in the sequence of DNA.
Two examples of epigenetic phenomenon include adding a
molecule to DNA or rearrangement of parts of a chromosome.
Scientists use mice to study changes in DNA
that could also occur in humans and that could eventually lead
to cancer 99 percent of mouse genes have analogues
in humans A chromosome is a single piece of coiled DNA
as well as protein molecules bound to the DNA,
which serve to package the DNA and control its functions.
Addition of methyl groups: When methyl groups,
which are a basic compound consisting of one carbon
and three hydrogen atoms, attaches to a strand of DNA
within a chromosome, this is an epigenetic phenomenon
which can alter DNA expression and ultimately lead
to a cancer outcome in the animal the event occurs in,
or in one of its progeny.
One other pathway for methylation
to occur is via histone involvement.
Histones are proteins which package and order DNA
into structural units.
They act as spools around which DNA winds.
Without histones, the unwound DNA
in chromosomes would be very long.
Methyl groups can also attach to the 'tails' of histones,
which leads to DNA unwinding, thereby decreasing the ability
of genes to be expressed, and hence the greater potential
for mutation, and eventually cancer, as seen occurring
in the progeny of this mouse.