Week 4 Flashcards
Where were the first embryonic stem cells derived from?come back
-early mouse embryos
- cells from the blastocyst would be plated in layers of fibroblasts
What are the properties of mouse embryonic stem cells?
- Murine Es cells(alkaline phosphatase positive cells) grow as right dome colonies on surface of monolayer feeder cells or on plastic surface treated with ECM
-these cells are AP positive like other pluripotent stem cells and it is an indicator of stemless/ pluripotency and an indicator of undifferentiated embryonic stem cells - the colony will turn red.
-these stem cells express transcription factors Oct 4 (which is important to regulate pluripotency/ ability to differentiate Into multiple mature cell types and self renewal properties) and nanog ( which is regulated by Oct 4 and contributes to cell fate determination of ICM)
What cell types can embryonic stem cells differentiate into?
- Cells that represent the three germ layers..
-the three basic techniques for ES cell differentiation are:
1. Embryoid body aka hanging drop method -> aggregation of the cells in suspension culture where the primitive endoderm which arises from the inner cell mass (ICM of the blastocyst) during embryonic development in on the outside and other lineages are on the inside
- Stomal cells -> feeder cells like OP9 stroll cells to feed the dispersed ES and when cultured with ES, causes differentiation into blood cells
- Matrix -> placing ES in defined matrix for example, collagen
What is the most commonly used technique for ES cell differentiation?
-embryoid bodies
What are the two main periods of prenatal development?
- Embryonic period – First 8 weeks.
- Fetal period – Remaining 30 weeks.
What are human embryonic stem (ES) cells?
Pluripotent stem cells derived from early-stage embryos, capable of differentiating into any cell type.
Why are embryonic stem cells controversial?
Ethical concerns arise due to the interference with early-stage human life.
What are some applications of embryonic stem cells?
- Human cloning.
- Experimental genetic engineering.
- Veterinary medicine.
- Rare species conservation.
What are the key stages of vertebrate embryonic development?
- 1-cell stage → 2. 8-cell stage → 3. Morula → 4. Blastocyst (outer embryonic layer + inner cell mass).
What is the role of the mammalian inner cell mass (ICM)?
ICM cells can be cultured as ES cells and give rise to the epiblast and hypoblast, leading to the three germ layers (ectoderm, mesoderm, endoderm).
How is the mouse epiblast significant in stem cell research?
Mouse epiblast cells can be cultured to derive pluripotent stem cells, providing a model for understanding human ES cells.
Who was Leroy Stevens, and what did he discover?
Leroy Stevens was a pioneer in stem cell research who linked teratocarcinomas (tumors containing multiple tissue types) to pluripotency and first isolated ES cells.
What is a teratoma?
A tumor composed of multiple tissue types, including hair, teeth, and cartilage, indicating the presence of pluripotent cells.
How was the 129 mouse strain important in ES cell research?
The 129 mouse strain had a high incidence of teratomas, making it a valuable model for ES cell studies.
What are embryonal carcinoma (EC) cells?
EC cells are undifferentiated cancer cells derived from teratocarcinomas, capable of differentiating into multiple tissue types.
What is the P19 cell line?
A standard model for pluripotent stem cell differentiation, used to study development and cellular specialization.
Which small molecules induce differentiation in EC cells?
- Retinoic acid → Neuronal and cardiac cell differentiation.
- Dimethylsulfoxide (DMSO) → Skeletal muscle differentiation.
How were the first embryonic stem cells derived?
They were isolated from early mouse embryos, specifically from the inner cell mass of blastocysts.
What is the role of feeder cells in stem cell culture?
Feeder cells provide a supportive monolayer that helps maintain the pluripotency and normal karyotype of stem cells.
What are the two main layers of the blastocyst?
- Trophectoderm (outer layer) – Contributes to the placenta.
- Inner cell mass (ICM, inner layer) – Contains pluripotent stem cells.
