Epigenetics

• What is epigenetics?

  • Heritable changes in gene function without changing DNA base sequence
• What do epigenetics do?

  • Control gene expression by adding chemical tags that turn the gene "on" or "off"
• What causes epigenetics?


  • Changes in environment such as stress, diet and toxins
• What are histones?

  • Proteins that DNA wraps around
• What is the epigenome?

  • The entire epigenetic sequence of an organism
  • (All of the chemical modifications to all histone proteins and DNA except base changes)
• What are the 2 chemical tags

  • Methylation
  • Acetylation
• What are transcription factors?

  • Factors that determine the rate of transcription and DNA replication
• What does increase methylation do?

  • Methyl groups bind to the DNA causing it to coil tightly to the histone, transcription factors can no longer bind to the DNA, this decreases transcription and DNA replication
• What does increase acetylation do?

  • Acetyl groups bind to the histone, this prevents DNA from tightly coiling to the histone, transcription factors can bind to the DNA, this increases transcription and DNA replication
• How can epigenetics cause cancer?

  • Increased methylation or decreased acetylation of a tumor suppressor gene, turns the gene "off" so the gene can no longer produce proteins that prevent cancer