1. Poll
30 seconds
Nature or Nurture: What has more influence on the behavior, health, skills, and traits of an organism - their DNA, or their environment?
- DNA
- Environment
- Both are involved
- Neither is involved
2. Slide
60 seconds
Can the environment of your ancestors affect your genes today?
3. Slide
60 seconds
4. Slide
60 seconds
The Influence of Environment on Gene Expression
Epigenetics
5. Slide
60 seconds
Explain the role of epigenetic mechanisms in gene expression Identify specific examples of how epigenetic modifications can be influenced by environmental factors Discuss inheritance of the epigenome
Learning objective:
6. Slide
60 seconds
Epigenetics is the study of changes in gene expression that do not involve changes to the underlying DNA sequence. Epigenetic mechanisms are responsible for controlling which genes are expressed and when. Epigenetic changes are heritable and can be passed down through generations.
Epigenetics: Rewriting Your Genetic Code
7. Poll
300 seconds
What is an epigenetic change?
- A change to the genetic code of an organism
- A change to the structure of a chromosome
- A chemical "tag" added to DNA that can alter the expression of a gene
- A change in behavior unrelated to genes
8. Word cloud
120 seconds
Word Cloud: What's an environmental factor that you think can lead to an epigenetic modification?
9. Slide
60 seconds
Diet and obesity physical activity tobacco use alcohol consumption environmental pollutants psychological stress disrupted sleep patterns
Epigenetics and Lifestyle
10. Slide
60 seconds
Examples of Epigenetic Influence on Gene Expression
11. Slide
60 seconds
Examples of Epigenetic Influence on Gene Expression
12. Slide
60 seconds
Common toadflax and peloric toadflax are identical in every way, except for the shape of their flowers. They are two variants of the same plant with a difference in one gene. But it’s not a difference in the DNA code. It’s an epigenetic difference. And peloric toadflax can pass on this “epimutation” to its offspring.
Examples of Epigenetic Influence on Gene Expression
13. Slide
60 seconds
Female water fleas respond to chemical signals from their predators by growing protective helmets. The offspring of helmeted water fleas are also born with helmets - even in the absence of predator signals. This effect continues to the next generation, though the helmets in the grandchildren are much smaller.
Examples of Epigenetic Influence on Gene Expression
14. Slide
60 seconds
When radish plants are attacked by caterpillars, they produce distasteful chemicals and grow protective spines. The offspring of caterpillar-damaged radishes also produce these defenses, even when they live in a caterpillar-free environment. The evidence of epigenetic inheritance in this case is indirect, though it’s highly likely that the information passes from parent to offspring through the reproductive cells.
Examples of Epigenetic Influence on Gene Expression
15. Slide
60 seconds
Feeding vinclozolin (a fungicide) to pregnant rats causes lifelong epigenetic changes in the pups. As adults, male offspring have low sperm counts, poor fertility, and prostate and kidney disease. The great-grandsons of the exposed male pups also have low sperm counts. Low sperm count persisted into the third generation, and the sperm had an abnormally high level of methyl tags.
Examples of Epigenetic Influence on Gene Expression
16. Slide
60 seconds
Geneticists analyzed 200 years worth of harvest records from a small town in Sweden. They saw a connection between food availability in one generation and the incidence of diabetes and heart disease in later generations. The amount of food a grandfather had to eat as a child was especially important. Boys form the cells that will give rise to sperm during early adolescence. Since the building blocks for the epigenome come from the food a boy eats, the epigenome may represent a snapshot of the boy’s environment that can pass through the sperm to future generations.
What about examples in humans?
17. Poll
300 seconds
Which of the following is true about epigenetic changes?
- They are heritable, but not permanent
- They are permanent, but not heritable
- They are permanent and heritable
- They are neither permanent nor heritable
18. Slide
60 seconds
Epigenetic Effects on Child Development: Epigenetics and the Human Brain: Nutrition and the Epigenome: Epigenetic Studies on Parental Care and Offspring Anxiety in Rats: Insights from Identical Twins: Epigenetics and Genomic Imprinting: Epigenetic Tags and Cellular Memory: Gene Control Interactive:
Learn more about Epigenetics
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