CB26 Stem Cells

Question 1

Define a stem cell

Answer 1

A stem cell is a cell that has the capacity to self-renew through asymmetric division and the ability to generate differentiated progeny.

Question 2

Define embryonic and adult stem cells

Answer 2

EMBRYONIC STEM CELLS

• present in the inner cell mass of the early embryo and gives rise to all cell types in the body (3 embryonic germ layers: 1. endoderm, 2. mesoderm, 3. ectoderm)
• considered PLURIPOTENT

ADULT STEM CELLS

• tissue-specific and responsible for the replenishment of organ systems
• considered MULTIPOTENT

Question 3

Explain how stem cells can be obtained from the embryo, foetus, and adult sources

Answer 3

In vivo / In vitro fertilisation
Problems:
- maintain pluripotency
- prevent differentiation
- maintain proliferation
- niche environment

Bone marrow in adult

Question 4

What is the concept for niche

Answer 4

Signals for division & maintenance of pluri/multipotency
Involve things such as physical contact & diffusable factors