(9) Stem Cells Flashcards
What is a stem cell?
Primitive cell; can either self-renew or give rise to more specialized cell types
What are the characteristics of stem cells?
- Not terminally differentiated
- Can divide w/out limit
- Undergo slow division
Adult stem cells are _________ specific
tissue
Proliferative potential =
potency
Define:
Totipotent
Give rise to ALL cells of an organism
eg: zygote
Define:
Pluripotent
Give rise to cells types of the EMBRYO and Subsequently adult tissues
eg: embryonic stem cells
Define:
Multipotent
Can give rise to different cell types of a given lineage
eg: adult stem cells
What are founder cells?
What is a transit amplifying cell?
- Divide frequently
- Transit from a cell with stem cell characteristics to a differentiated cell
Maintenance of stem cells:
What are the types of asymmetry?
- Divisional asymmetry
- Environmental asymmetry
Maintenance of stem cells:
What is the importance of asymmetry in stem cell division?
Able to create one differentiated cell type, retain one stem cell
What is the immortal strand hypothesis?
-Some tissues’ stem cells selectively retain original DNA
Embryonic stem cells are derived from the _______
blastocyst
Embryonic stem cells are capable of proliferating _______
indefinitely
Embryonic stem cells have _______ developmental potential
unrestricted
Embryonic stem cells give rise to _______
tertomas
Genes in pluripotent cells:
What are the transcription factors that are essential for establishment and maintenance of pluripotent stem cells?
- Nanog
- Oct4
- Sox2
- FoxD3
Cripto and GDF-3 are ______
growth factors found in pluripotent cells
Adult stem cells respond to:
demands of growth and repair
-STRICTLY imposed by molecular restraints on gene expression
What is a major limitation with use of adult stem cells?
Immune rejection
What are the two alternative sources for Human ES cells?
- Induced Pluripotent Stem (iPS) cells
- Somatic cell nuclear transfer (SCNT)
Induced Pluripotent Stem Cells:
Describe:
Take fully differentiated adult cells and return them back to pluripotent state
iPS cells have a ________ teratoma potential than native ES cells
HIGHER
Dolly the sheep was created via ________
Somatic cell nuclear transfer