Lecture 16 & 17: Stem Cells and Cloning Flashcards
What are the 3 characteristics of a stem cell?
1) Self-renewing
2) Unspecialized
3) Can give rise to specialized cells
How is a stem cell “self-renewing?”
Capable of dividing and renewing themselves for long periods
How is a stem cell “Unspecialized?
Do not have any tissue-specific structures that allow them to perform specialized functions
How is a stem cell give rise to specialized cells?
Differentiation causes cell’s DNA to acquire changes that restrict DNA expression in cell and can be passed on through cell division
Totipotent Stem Cells
can develop into ___ cell in body; including ____ membranes
Any;
Embryonic
What is a Blastomere?
A single cell from a 2-8 day cell or a 1-3 day embryo
Totipotent Stem Cells
are sufficient to form _____ organism capable of ____, including ____-_____ membranes
Enitre;
Reproduction;
Extra-Embryonic
Pluripotent Stem Cells
Can develop into ____ from all 3 germ layers and germ cells
derivatives
What are the 3 germ layers?
what are the 2 germ cells?
Ectoderm, Mesoderm, Endoderm
Eggs and Sperm
Multipotent/ Precursor/ Progenitor Stem Cells
Can become specialized cell but generally only in ___ or ____ in which it resides
Tissue
Organ
How do you make embryonic (pluripotent) stem cells?
1) Create Embryo
2) Remove inner cell mass from blastocyst (Day 5)
3) Culture cells
Traditional methods of making embryonic stem cells involves:
creating stem cells from inner cell mass of embryos
Removing ICM destroys the embryo,
T/F
True
When culturing Embryonic Stem Cells, they are coated with____ ____
Feeder Cells
What are the 4 tests to identify embryonic stem cells?
1) grow and sub-culture cells for many months
2) Look for surface markers or proteins found only in undifferentiated cells
3) Examine chromosomes under microscope
4) Determine if cells can be grown and sub-cultured after freezing, thawing and re-plating
What is the fifth step of testing embryonic stem cells?
Test for pluripotency
What 4 things happen during testing for pluripotency?
1) Allows for spontaneous differentiation
2) Stimulate directed differentiation
3) Inject cells into immuno-suppressed mouse to test for formation to benign tumor (teratoma)
4) Tetraploid-embryo complementation
What happens during Spontaneous Differentiation?
(3)
(Emborid Bodies)
Allows cells to clump together to form 3-D structures
- Method to determine if embryonic stem cells culture is healthy
- Not efficient way to produce cultures of specific cell type
What happens during Directed Differentiation?
Used to generate large number of specific cell types
- alter surface of culture dish
- Change chemical composition of culture medium
- Modify cells by inserting specific genes
What happens during Teratoma Formation?
test differentiation capacity of stem cells by injecting them into immuno-suppressed mouse and inducing formation of teratoma
What are some of the challenges of Regenerative Medicine?
- Proliferate extensively and generate sufficient qualities of tissues
- Differentiate into desired cell types
- Be free of animal products
- Survive in recipient after transplant
- Integrate into surrounding tissue after transplant
- Function appropriately for duration of recipient’s life
- Avoid harming recipient in anyway
Transplanted stem cells may not cause immune rejection by recipient.
T/F
False, it can cause
This technology used to generate an individual who has the same DNA as another currently or previously existing individual is called?
Reproductive Cloning
Generation of human embryos for use in research to harvest stem cells that can be used to study human development and treat disease is called?
Therapeutic Cloning
Only clones ___ ____ is the same as that of a ____ donor
Nuclear DNA;
Somatic
_____ contain their own short segments of DNA
Mitochondria
Some of the clone’s genetic material come from ____ in cytoplasm of _____ eggs
Mitochondria
enucleated
Mitochondrial DNA contain ____ protein-coding genes
Nuclear DNA contain _____ protein-coding genes from each patient
13
23,000
Mitochondrial Replacement require genetic contribution from 3 parents, which are?
1) the intended mother with the mitochondrial disease
2) Intended father with the sperm
3) a female egg donor with normal mitochondrial
What is Gene Therapy?
Genes that are used to treat or prevent disease
What is Cell Therapy?
Cellular material is injected into diseased patient
What cells are targeted for gene therapy?
what do they do?
Adult Stem cells: treat only diseases in affected individuals
Embryonic Stem cells: Whole genome or germ-line modification will be passed down to offspring
