What is cell determination?
- A process by which a single fertilised cell (Zygote) divides into multiple cells, groups of these cells gradually become committed to specific patterns of gene activity
- A progressive fixation of the fate of a cell’s descendants
What are mesenchymal stem cells?
- Undifferentiated mesodermal cells of the embryo which will differentiate into muscle and connective tissue
What is differentiation?
A pathway whereby cells make genetic commitments (regarding the differential expression of genes) and gradually restrict the development of the descendants of that cell to a limited set of final tissue types
What is cell differentiation?
- The final step leading to cell specialisation
- Once this point is reached the process is irreversible
Stem cell?
An undifferentiated cell of either embryonic or adult origin which can undergo unlimited division and give rise to one or several cell types
What are the most versatile stem cells?
Zygotes, they produce all of the cell in the body (totipotent)
Totipotent stem cells?
Potential to give rise to all tissues of the body and placenta
Pluripotent stem cells?
Can give rise to many of the types of cells in an organism, but not all
What are the two basic cell types that exist?
Germ Cells and somatic cells
Germ Cells?
- Can divide by meiosis and produce a new generation of individuals (sex cells)
- Very first cell to differentiate
Somatic cells?
Are all the cells of the body except germ cells
Stem cells are potential sources for cell transplantation into patients to treat what serious degenerative conditions?
- Dopamine-producing cells for Parkinson’s Disease
- Insulin-producing cells for diabetes mellitus
- Replacement neurons for spinal cord injury or other types of neurological damage
Human reproductive cloning?
Has the goal of producing a newborn human that is genetically identical to another human adult
Human therapeutic cloning?
Involves duplication of human ES cells or iPS cells for scientific study or medical purposes
Parthenogenesis?
Reproduction from an ovum without fertilisation. It occurs naturally in certain plant species, invertebrate animals and even vertebrates (e.g. somefish, amphibians,reptiles )
Bee example of parthenogenesis?
Female eggs are produced sexually, using sperm from a drone father, while the production of further drones (males) depends on the queen (and occasionally workers) producing unfertilised eggs. This means that females (workers and queens) are always diploid, while males (drones) are always haploid
Human parthenogenetic stem cell (hpSC)?
- Another type of embryonic stem cell
- Stem cells are created by chemically stimulating the oocytes (eggs) to begin division. The oocytes are not fertilised and no viable embryo is created or destroyed
Autologous source?
Coming from the same person
Allogeneic source?
Coming from a different person/donor
Same DNA?
Nuclear equivalence
How do you know that you’re dealing with a line of pluripotential stem cells?
- They can form red blood cells, smooth muscle and neurons
- Tumours can develop and if it contains tissue from each of the 3 germ layers then it’s pluripotent
3 germ layers produced by somatic cells?
Endodermal, ectodermal and mesodermal
