Stem Cells Flashcards
The highest level of potency, of which zygotes are.
Totipotent
__________ is the ability to give rise to all cells of the embryo and subsequently adult tissues.
Pluripotency
The ability to give rise to different cell types of a given lineage (adult stem cells)
Multipotency
Pluripotent stem cells come from what part of the blastocyst?
The inner cell mass
How are the number of founder stem cells determined?
They are proportional to the number of cells that are in a mature human (there are more skin cells than heart cells)
How often do transit amplifying cells divide? How many times do they divide?
They divide frequently but they are programmed to have a limited number of divisions
What are the two ways that stem cell amounts are maintained?
Divisional asymmetry - stem cells keep their immortal DNA separate so that the cells can continue dividing
Environmental asymmetry - stem cells are kept sequestered in their own area while the cells destined for normal use are moved to their final area
What is the name of the thing that makes a stem cell a stem cell?
Localized determinant
How do embryonic stem cells divide?
Egg and sperm meet -> zygote is formed (totipoent) -> blastocyst (pluripotent) -> fetus
The inner cell mass of the blastocyst can be cultured to make pluripotent stem cells
What are the characteristics of embryonic stem cells?
They are derived from blastocysts
They are capable of proliferating indefinitely
They have unrestricted developmental potential
They can also give rise to tumors
Embryonic stem cells can also give rise to _______________ (cancer type). What can be done to prevent this?
Teratoma, need to differentiate cells fully before stem cell treatment
What are the transcription factors required for induction of pluripotent stem cells?
Nanog, Oct4, Sox2, FoxD3
What can hematopoietic and stromal stem cells produce?
HSC can make blood components
MSC can use connective tissues and other tissues
What is a major issue with adult stem cell use?
Immune rejection
What is an alternative to stem cells? How does it work?
Somatic cell nuclear transfer
The nucleus is taken out of an egg cell and discard and then the cell is fused with a somatic cell, effectively transferring the nucleus
