Introduction to Stem Cells Flashcards
What are the properties of stem cells
- Different into many cells of a particular tissue in that lineage
- Self renewal: indefinite properties to continuously self produce cells
Describe what is formed in embryonic development
Zygote into Blastocyst into Gastrula
What are the different layers that make up a gastrula and the different cells it produces?
Ectoderm: External
Skin cells
Neuron of brain
Pigment cells
Germ cells:
Egg and sperm
Endoderm: Internal
Lung cell (alveolar cell)
Thyroid cell
Pancreatic cell
Mesoderm: Middle Cardiac Muscle Skeletal muscle cell tubule cell of kidney Red blood cells Smooth muscle in gut
In the zygote, where do we find the embryonic stem cells
In the inner cell mass
What is totipotent
Can make all the cells necessary to generate an organism
What is pluripotent
Can make all the cell types of the body, but cannot make an organism alone: cannot make placenta
What is multipotent
Can make any tissue specific cell lineage depending on their type: they may go bipotent
Example: Stem cell can become muscle, nerve, bone etc
What cells make the myelin sheath
Oligodendrocytes
If all cells have the same DNA, why do they become different cells
Has the same DNA but expresses different levels of gene
Modification to histones can change whether a gene is silenced or active
How does directed differentiation happen and give an example?
- Depends on signal environment surrounding the stem cells
- Differentiates into different cells
For example:
Common myeloid progenitor made from: IL-1, IL-3, IL-6, GM-CSF, SCF
What is somatic cell nuclear transfer
- An embryo is used to make a stem cell (pluripotent)
- Somatic cell + enucleated oocyte
- Dolly the sheep
What may occur in transplantation therapy of embryonic stem cells
Produce and replicate to cause cancer (tumorigenic)
May have rejection
Terrortomas
Need to make sure no pluripotent cells left to turn into cancer
Give some potential uses of stem cells
Stroke Alzheimer's disease Parkinson's disease- forming neurons Baldness Blindness Deafness Myocardial infarction- cardiac muscle Wound healing Bone Marrow Transplant Diabetes- reforming of pancreatic beta cells
What can the bone marrow produce
Liver cells Skeletal muscles Brain Blood cells Blood vessels Cardiac muscle Epithelial cell Neuron: Glial cells
What are the ethics behind stem cell research and methods used that are at the centre of the controversy
Main issue: destruction of embryos
Somatic cell nuclear transfer
