Exploring the Impact of Epigenetics

Apr 9, 2025

Epigenetics | PBS LearningMedia

Overview

  • Epigenetics is the study of the epigenome, which consists of chemical switches affecting gene expression.
  • The epigenome dictates cell identity and function, influencing which genes are active or inactive.
  • Epigenetics explores how environmental factors and lifestyle choices impact gene expression.

Key Concepts

The Epigenome

  • A secondary layer of information on DNA, controlling gene expression.
  • Functions like a "chemical switch" turning genes on or off.
  • Plays a role in cell differentiation (e.g., brain cells vs. hair cells).

Research and Applications

  • Studies focus on chemical changes affecting gene expression without altering DNA sequences.
  • Methylation: Addition of methyl groups to DNA, influencing gene expression.
  • Environmental factors affecting epigenetics:
    • Heavy metals
    • Pesticides
    • Tobacco smoke
    • Radioactivity
  • Links between epigenetic mechanisms and diseases like cancer, cognitive dysfunction, and autoimmune diseases.

Epigenetic Research in Disease and Therapy

  • Cancer:

    • Epigenetic changes can lead to over-expression of genes, causing cancer.
    • Tumor-suppressing genes might be switched off, leading to uncontrolled cell division.
    • Goal: Change cell instructions rather than kill cells.

  • Stem Cells:

    • Challenge in controlling stem cell differentiation.
    • Epigenetic modifications may guide stem cells to develop into specific tissue types.
    • Potential for targeted stem cell therapies.

Significant Insights

  • Differences in identical twins can be explained by epigenetic changes.
  • Older twins show more significant epigenetic differences due to environmental and lifestyle factors.

Discussion Questions

  • Differences between brown and yellow mice due to epigenetic variations.
  • Role of DNA methylation in cellular function.
  • Why genetically identical twins are not truly identical.
  • Factors contributing to DNA differences in older vs. younger twins.

Educational Context

  • Target Grades: 9-12
  • Part of the NOVA Collection focusing on biotechnology and genetics.
  • Supports understanding of NGSS and Benchmarks for Science Literacy.
  • Support Materials:
    • Background Essay
    • Discussion Questions

Additional Resources

  • Related topics in genetics, bioethics, and environmental effects on traits.
  • Further exploration in NOVA's collection of science resources.

Note: For more detailed educational materials, background readings, and discussion questions, visit PBS LearningMedia.