Cellular Differentiation, Stem Cells and Modern Medicine Flashcards
How does an embryo begin?
As a small number of naive, totipotent cells
What does totipotent mean?
A cell than can give rise to all parts of the embryo and adult as well as extra embryonic membranes (placental) in species that have them
What can embryonic stem cells give rise to?
All cell types except trophectoderm (they are pluripotent)
What does pluripotent mean?
A cell (immature or stem) capable of generating all the cells of an embryo with the exception of placenta
What happens to a cell as it develops?
It becomes more specialised and less flexible
When does the restriction of the cell stop?
When it becomes terminally differentiates and can only give rise to the same type of cells
What are the exceptions to cells becoming more specialised and less flexible during development?
Stem cells and germ cells (sperm and egg)
What are the stages of embryo development?
8 cell stage»_space;> Cell polarisation»_space;> Compaction»_space;> Inner, apolar cells cut off»_space;> Blastocyst
What does a blastocyst consist of?
Inner Cell Mass (ICM) which is the embryo and the trophectoderm which is the placenta
What are embryonic cells?
Non-differentiated (pluripotent) and contain genetic information to make any type of differentiated cell. Muscle specific genes are not being transcribed
What happens when the cell becomes a myoblast (determined)?
The cell must now develop into a muscle cell. Certain control genes which code for transcription factors are actuated and so transcription factors are produced.
What happens when the cell becomes terminally differentiated?
The transcription factors are able to turn on other genes to make other transcription factors and other proteins forming a fully functioning cell that plays a role in the organism
What is meant by genomic equivalence?
Differentiated cells contain all the DNA required to build an entire new organism
How are embryonic stem cells obtained?
They are harvested from the inner cell mass (future embryo) of mammalian cells
How do the cells derived from embryonic stem cells compare to the embryo donor?
They are genetically identical