Lecture 5: Stem Cells and Application Flashcards
What are characteristics of stem cells?
- Not terminally differentiated
- Can divide without limit (divides slowly)
- Gives rise to 1 stem cell and 1 differentiated cell
What it totipotency?
Ability to give rise to all types of cells (embryonic and extra embryonic)
-Zygote totipotent until 16 cells
What is pluripotency?
Ability to give rise to all embryonic cells and adult tissues
What is multipotency?
Ability to give rise to different cell types of a given lineage
What is unique about founder stem cells?
Decided early which cells become which body parts
- fixed number of founder cell populations
- fixed number of divisions
What are transit amplifying cells?
Cells that divide quickly
- go from stem cell to differentiated cells
- finite number of divisions
How do stem cells ensure that one daughter cell is a stem cell and the other is a terminally differentiated cell?
Divisional Asymmetry
Environmental Asymmetry: changes cell after division
What is the immortal strand hypothesis?
Some stem cells with retain original DNA and cells are synthesized from that
What are embryonic stem cells?
Derived from blastocyst stage and has unrestricted developmental potential
-can integrate well in blastocyst but not in future stages
What are teratomas?
Cells that can develop into different tissues but do not have axis formation or segmentation
-lack of organization
What important transcription factors are essential for establishment and maintenance of pluripotent cells?
Nanog
Oct 4
Sox 2
Fox D3
GCNF: early stages
What are important growth factors for pluripotent cells?
Cripto and GDF-3
Where do hematopoietic and stromal stem cells come from?
Bone marrow
-can become blood or connective tissues
What are the goals of adult stem cell therapies?
Program bone marrow stem cells or adipose into pluripotent induced cells to regenerate other types of cells (e.g. neuronal cells)
What are somatic cell nuclear transfer cells?
1) Egg cell has nucleus removed
2) Egg cell fuses with somatic cell
3) Cell division occurs
4) Extract cells from blastocyst for cultured pluripotent embryonic stem cells
