15.3: Environmental Epigenetics

Question 1

What does differentiation of stem cells into specific cell types require?

Answer 1

epigenetic modifications- programmed epigenetic remodeling

Question 2

What could research into stem cells help us understand?

Answer 2

• disease
• generate healthy cells to replace damaged cells “regenerative medicine”
• test new drugs for safety/efficacy

Question 3

What are totipotent embryonic stem cells?

Answer 3

the first stem cells which can differentiate into anything

Question 4

What are pluripotent embryonic stem cells?

Answer 4

• endo, meso, and ecto derm
• due to epigenetic modifications

Question 5

What are multipotent cells?

Answer 5

adult stem cells

Question 6

What are unipotent somatic cells?

Answer 6

the final somatic cells (can only make one thing)

Question 7

Where are totipotent and pluripotent stem cells found?

Answer 7

• in fetal tissue
• embyronic stem cells can be replicated in lab conditions, without inducing differentiation

Question 8

Where can multipotenet adult stem cells be found?

Answer 8

in small numbers in some tissues in adults or children

Question 9

What is happening to reduce the reliance on fetal tissue?

Answer 9

• ongoing efforts to reprogram adult stem cells to pluripotent stem cells
• works for some adult stem cells

Question 10

How does epigenetics contribute to memory and learning?

Answer 10

• During memory formation, a set of genes (IEGs- inducible early genes) are rapidly expressed in the brain. Many of these IEGs have an RNA polymerase bound to the promoter, but are not yet transcribing
• Associated fear learning refers to the ability to learn that a specific sensory cue can predict an adversive event
• During associated fear memory formation, DNA topoisomerase II beta (TOP2B) induces ds breaks in the promoters of certain IEGs.
• At promoters where RNApol is bound, the ds break allows the +1 site to phyiscally move to its enhancer element, allowing transcription initiation