Epigenome

Epigenome

IDENTICAL TWINS: PINPOINTING ENVIRONMENTAL IMPACT ON THE
EPIGENOME

1. Often, the physical characteristics of genetically identical twins become increasingly
different as they age, even at the molecular level. Explain why this is so. (use the
terms "environment" and "epigenome")
Physical characteristics of genetically identical twins become increasingly different as they age by one major reason which is environmental factors such as level of stress, smoking, your diet, and even your exposure to the sun. These factors impact the epigenome by turning genes on and off to determine which characteristics are expressed. If one twin smokes and another doesn't the genes on one will be different than the other causing different physical and molecular characteristics. This increases during aging due to more factors encountering the epigenome.

2. Name 3-4 environmental factors that influence the epigenome.
Stress, smoking, diet, and exposure to sun are all environmental factors that influence the epigenome.

3. What is an imprinted gene?
Imprinted genes are genes whose expression is determined by the parent that contributed them.

YOUR ENVIRONMENT, YOUR EPIGENOME

1. Discuss factors in your daily life (ie. Diet, exercise, stress etc.) that could be affecting
your epigenome. Stress and exercise are factors that can be effecting my daily life the stress can even control my exercise achievements.

1. Explain how a high-nurturing mother rat shapes her pup's epigenome, and what that
pup's response to stress will be. When a high-nurturing mother rat shapes her pup's epigenome she licks the pup constantly and the response will become relaxed to stress.

2. In rats, does licking by the mother activate, or deactivate her pup's GR gene? Rats (and people) with higher levels of GR are better at detecting cortisol, and they recover from stress more quickly. GR helps shut down the stress response. Stress circuitry activates the adrenaline-driven Fight or Flight response and causes the hormone cortisol to be released into the bloodstream.

3. Explain how cortisol and the GR protein work together in the brain to relax a rat pup.
You may draw a diagram. Stress signals travel from the hypothalamus to the pituitary gland and then to the adrenal glands. The adrenal glands release the hormone cortisol.

4. The rat nurturing example shows us how parental behavior can shape the behavior of
their offspring on a biochemical level. Relate this to humans and think about the personal
and social implications. Record your thoughts. When we over nurture and take things carefully and really nurture the end result is a calm and understanding person with balance and a great base and blocks to build. When we don't nurture or care about someone they end up up not knowing what to do, no structure at all.

UTRITION & THE EPIGENOME

1. Explain how the food we eat affects gene expression.
Diet is one of many environmental factors that turn genes on and off to be expressed. Unhealthy diet choices may lead to a unhealthy body.

2. Can the diets of parents affect their offspring's epigenome?
Yes, records show that food availability between the ages of nine and twelve for the paternal grandfather affected the lifespan of his grandchildren. Shortage of food for the grandfather was associated with extended lifespan of his grandchildren. Food abundance, on the other hand, was associated with a greatly shortened lifespan of the grandchildren.

EPIGENETICS & THE HUMAN BRAIN

1. How does Dietary methyl influence gene expression ?
Methyl groups (tags) do the job of silencing genes so that they are not expressed. Diets high in these methyl-donating nutrients can rapidly alter gene expression, especially during early development when the epigenome is first being established.

2. Why do Toxins affect gene methylation? Exposure to BPA(toxin) during early development had caused decreased methylation of the agouti gene.