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What are stem cells?
Cells found in the early embryo and in other parts of the human body that are not fully differentiated.
What are the general properties of stem cells?
Capable of dividing and renewing themselves for long times
Undifferentiated, but has the capacity to develop into differentiated cells
Where can stem cells come from?
Embryonic Stem Cell
Stem Cells from Umbilical Cord
Adult Stem Cells
What is an Embryonic Stem Cell?
They make up the inner mass of cells of the blastocyst that exists in the 1st week of development.
How many stem cells from umbilical cord blood is collected?
100 mL collected with 1.5x10^5 CD34+ cells from placenta during 3rd stage of delivery/post-delivery.
What are Adult Stem Cells?
Cells from bone marrow and peripheral blood
How many stem cell types are there?
Four.
Totipotent
Pluripotent
Multipotent
Adult
What are some characteristics of Totipotent stem cells?
Most versatile
Totipotent = one-celled
Can be any and all human cells
Can rise to functional organisms
How many days does it take for Totipotent stem cells to specialize into Pluripotent stem cells?
Four days.
What are some characteristics of Pluripotent stem cells?
Can give rise to all tissue types
Cannot make an entire organisms
What are Induced Pluripotent Stem Cells? (iPSCs)
Adult cells genetically converted to an embryonic stem cell-like state.
When were iPSCs introduced?
2007, for human cells.
In animal studies, what have iPSCs shown?
Shown to possess pluripotent stem cell characteristics
What are Multipotent stem cells?
Less plastic, more differentiated
Can give rise to a limited range of cells within a tissue type
What are Adult Stem Cells?
Multipotent stem cell in adult humans used to replace dead cells.
What are some Adult stem cell characteristics?
Undifferentiated cell present in differentiated tissue
Self-renewing
Can yield all cell types present in its origin tissue
What are some tissue types that Adult Stem Cells been identified for?
hematopoietic (blood)
endothelial
muscle
mesenchymal
epidermal cells
neural
gastrointestinal
What are some clinical applications of Stem Cells?
Diabetes
Leukemia
Nervous System Diseases
Primary Immunodeficiency Diseases
Diseases of Bone and Cartilage
Cancer
What is a clone?
An exact genetic copy of a molecule, cell plant or animal.
What are the three cloning methods?
DNA
Therapeutic/embryo
Reproductive
What is involved in DNA cloning?
Only the DNA of a cell is replicated
It is the transfer of a DNA fragment from one organism to a self-replication genetic element (such as a bacterial plasmid)
DNA of interest can be spread in a foreign host cell.
What is the possible applications of DNA cloning?
Gene Therapy
Gene Sequencing
What is involved in Gene Therapy?
Experimental
Introduces cells that compensate for abnormalities
or give benefits
This may be used to treat disorder instead of drugs or surgery
What are some approaches to Gene Therapy?
Replacing mutated gene with healthy copy
Inactivating a mutated and improperly functioning gene
Introducing a new gene to fight disease
What is Gene Sequencing?
Technique for determining the exact sequence of nucleotides, or bases, in a DNA molecule.
What is Therapeutic/Embryo Cloning?
Production of human embryos for treatment/research
Nucleus of bodily cell is inserted into an unfertilized, no-nucleus egg
Egg is stimulated to become embryo
Stem cells in the blastocyst would be identical to the person whose cell it was
What is Reproductive Cloning?
Technology used to generate an animal with the same nuclear DNA as another animal.
In reproductive cloning, what is Somatic cell nuclear transfer? (it’s a three-step process)
Transfer of genetic material from donor adult cell nucleus to an egg with a removed nucleus
Egg treated with chemicals/electric current for cell division
Once egg reaches suitable stage, it is transferred to female host uterus
What are some possible applications for Reproductive Cloning?
Repopulating endangered animals
Production of genetically altered animals that would serve as models for studying human disease.
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