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.
As people age, the a greater difference in environmental occurs. While they are younger (birth to toddling ages), they are more closely related because they haven't really had the time to see more of the world and make their own decisions and develop different habits.
2. Name 3-4 environmental factors that influence the epigenome.
Diet, habits (exercise or tv), toxins (smoking), and stress amounts.
3. What is an imprinted gene?
An imprinted gene is a epigenetic tag that instead of being erased during the first days after fertilization, are kept and the child is born with these tags turned on or off.
YOUR ENVIRONMENT, YOUR EPIGENOME
1. Discuss factors in your daily life (ie. Diet, exercise, stress etc.) that could be affecting your epigenome
The fact that I don't like bananas (awful little things) is probably not doing me any good because it means I won't be getting potasium, whatever that is. But the fact that I listen to my music out-loud when I can and as low as it can go will lead me to have less of a risk of hearing-impairment problems when I'm older.
LICK YOUR RATS
1. Explain how a high-nurturing mother rat shapes her pup's epigenome, and what that pup's response to stress will be.
A rat mother who constantly licks her pups will produce cortisol more readily which will bind to GR protein and calm the wel nurtured rat quicker than the neglected rat.
2. In rats, does licking by the mother activate, or deactivate her pup's GR gene?
It will activate the gene.
3. Explain how cortisol and the GR protein work together in the brain to relax a rat pup. You may draw a diagram.
When rats are agitated, animals go into this fight or flight instinct, where they will flee from the danger or fight it. However, with well nurture rats, soon after the danger has passed, more cortisol is released which binds to the GR protein which will then send out calming signals to the rat. Where a maltreated rat will take longer to calm down because less cortisol is released.
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.
Now a days, the more open, fun, and accepting a family is, the kid is more confident, chirpier, and accepting as well. The page kind of gave an example of this with the rats. A well nurtured rat in human society would fit in nicely and be sociable, whereas a low-nurtured rat would have a harder time fitting in because it would be anxious and paranoid. However, in the wild, it is a good thing to be anxious because those rats are more alert to danger in a land of scarce food vs. a happy-go-lucky rat. So low nurtured rats would make poor humans and high nurtured would good people.
NUTRITION & THE EPIGENOME
1. Explain how the food we eat affects gene expression.
Extracted nutrients are manipulated, modified, and molded into molecules, sometimes that molecule is important in making epigenetic tags that turn off genes. The molecules that will be helping epigenetic tags go through the methyl pathway in the metabolism who, in the end, put the modified molecules into our DNA.
2. Can the diets of parents affect their offspring's epigenome?
Yes, they can. For example, a lack of methyl-donating folate or choline during late fetal or prenatal development in a child leads to a methyl deficiency for life. With rats, a mother can malnourish her rats without eating methyl for the agouti gene which will cause her pups to have a yellow coat and be fat. Whereas healthy, methyl nourished pups will be thinner and have a brown coat.
EPIGENETICS & THE HUMAN BRAIN
1. How does Dietary methyl influence gene expression?
A higher level of methyl leads to a less active RNA, leading to a less active ribosome, meaning less protein which occurs in a greater number of people who commit suicide. Those who commit suicide have a gene for REEELIN protein which has less methyl (so is more active) that normal schizophrenic brains. This protein is crucial for the shaping of the brain in the early years and later on for learning.
2. Why do Toxins affect gene methylation?
Some toxins affect methylation because they treat the mental illness by changing the gene expression. The expressions are then stabilized through "epigenetic mechanisms" (DNA methylation and histone modification) which will reverse the effects of the disease. Harmful drugs, such as cocaine, will cause epigenetic changes in specified brain regions which will affect hundreds of genes in one go. Some of these changes are irreversible and are for life, even after the lack of exposer to the drug. It's theorize that long-term effects of drug abuse, addiction, and high rate of relapses is due to the epigenetic code.
