other

Question 1

experiment that showed being lied to overpowers genes

Answer 1

FTO gene
- variations:
A/A - less satisfied with a meal – eats more
A/T - stronger neurological responses to food images
T/T - lower responsiveness of gut peptides that signal fullness
- Measured after giving the same meal (480kcal):
-Self-reported satiety
-Acyl-ghrelin - makes hunger difficult to ignore
-GLP-1 – physiological indicator of satiety
- People lied to about protective or high risk version of the gene
- those who believed they had the protective version reported feeling more full after meals + GLP-1 levels were 2.5x higher than before - indicating a stronger satiety response
- people who were told they had the high-risk version reported no change in any measurements

Question 2

yellow agouti mouse example of epigenetics

Answer 2

• control group = fed a regular diet and remained yellow, prone to obesity, and at risk for type 2 diabetes
• tested group = fed with enriched nutrients (mouse chow, folic acid, vitamin B) showed notable changes: coat color turned brown, displayed less obesity and diabetes risk
• shows addition of methyl groups (CH3) to the DNA alters gene expression without changing the DNA sequence itself - methylation modified the coat color and metabolic health of the mice

Question 3

micro RNA’s and stress example of how environment affects genetic expression

Answer 3

• Control group – mice treated normally
• Tested group – stress out baby mouse by taking away from mother at difference times of day
• Tested group grew up to be depressed and risk-taking – do not fight for their lives in potentially harmful situations (move through exposed parts of mazes slowly) + don’t take pleasure in sugar water like normal mice
• Sperm and egg from unstressed parents + micro RNAs from sperm of stressed mouse into zygote = depressed and risk-taking pups, despite good childhood

Question 4

how do humans genes react to epigenetic upregulation

Answer 4

• certain genes can be upregulated (activated more strongly) due to early-life trauma:
  Major depressive disorder
  Anxiety
  Ptsd
  Substance abuse
  Suicide attempts
• Specific genetic variations (Variation 1) combined with trauma can cause these effects, whereas others (Variation 2) might not show changes

Question 5

example of how Trauma effects can be passed from parents to offspring in humans

Answer 5

• Children of mothers with PTSD from the Holocaust showed a tendency toward PTSD
• Children of fathers with PTSD were more likely to experience MDD (major depressive disorder)
• These effects persisted even if the children were not raised by the parents directly - shows an epigenetic component, not just an environmental one