Learning Objectives
Key Concepts
- Eukaryotic gene expression is regulated at the levels of transcription, RNA processing, translation, and post-translation.
- Proteins called transcription factors bind to DNA and control transcription. Different types of transcription factors can increase or decrease transcription.
- Mutations in DNA regions that control gene expression can alter the way genes are expressed.
- Infants have high lactase levels so that they can digest their mothers’ milk, but lactase gene expression is turned off after weaning.
- Lactase persistence is the trait that allows adults to continue to digest milk. It results from a mutation in an enhancer region of the lactase gene.
Teaching Notes
- Lactase persistence is an example of recent human evolution. It also illustrates how a mutation in a gene’s regulatory region can alter the gene’s pattern of expression.
- The related Click and Learn titled “Recent Adaptations in Humans” discusses the evolution of lactase persistence.
- This Click and Learn contains a detailed look at how eukaryotic gene expression is regulated—in particular, how DNA transcription is regulated.