18_Cell proliferation, tissue renewal and stem cells Flashcards
What was fused to form thee egg implanted in reproductive cloning of Dolly the sheep?
An enucleated egg from one sheep breed + a nucleus of a differentiated mammary gland cell from a different breed
During which stage was the fused egg implanted in reproductive cloning?
blastocyst stage
What are the genetic contributions of the EGG donor in reproductive cloning?
mitochondrial DNA
Where are embryonic stem cells found in the developing blastocyst?
Inner cell mass
What step differentiates reproductive and therapeutic cloning?
Whether or not the blastocyst is implanted
Stem cells are capable of self-renewal and commitment. What is the difference between these two?
Self-renewal: produce cells similar to SC in their capacity to proliferate and differentiate
Commitment: produce cells committed to differentiate
Embryonic stem cells are (toti/pluri/multi)potent.
Pluri
What is an example of a totipotent stem cell?
the zygote
What cell types are embryonic stem cells unable to produce?
the extraembryonic tissue cells (amniotic sac + placenta)
Which type of stem cells are tissue-specific and multipotent?
adult stem cells
Which type of cells exhibit global DNA demethylation?
Totipotent stem cells (i.e. zygote)
The egg and sperm are (differentiated/undifferentiated) cells.
Differentiated
What replaces histones in sperm?
Protamines
What induces the release of protamines from sperm chromatin?
egg microenvironment (chemicals in egg)
What is the definition of plasticity in the context of stem cells?
The ability of a partially differentiated adult stem cell to change its genetic program and differentiate into a cell of another tissue type
