cells alive 7- stem cells Flashcards
what are stem cells?
a cell that has the ability to continuously divide and differentiate into various other kinds of cells/tissues
what are the 3 types of stem cell?
- totipotent
- pluripotent
- mulitopotent
what are totipotent stem cells?
each cell can develop into a new individual cell
what are pluripotent stem cells?
cells can form any cell type
what are mulitpotent stem cells?
cells differentiated, but can form a number of other tissues
what are the stages of embryogenesis?
- cleavage: 2 cells
- 8 cell stage: totipotent
- blastocyst: have pluripotent stem cels
- blastocyst inner mass cells
once cells are fully differentiated what are they called and what does this mean?
- unipotent
- they can still replicate (with limits) but they will only give rise to cells with identical phenotypic characteristics
what is meant by stem cell niche?
- area of the tissue in which the stem cells reside in a quiescent (dormant) status, they arent doing anything
- cell to cell and cell to ECM interaction influence the fate of these stem cells
- These stem cells will get signals when they stem cells are needed
- maintenance of quiescence
- self renewal
- differentiation
name the locations of stem cell niches
- bone marrow
- skin
- central nervous system
- gut
- muscle
what is differentiation?
process by a cell become specialised
where are stem cell niches found in bone marrow?
near osteoblastic lining
where are stem cell niches found in skin?
in bulge of hair follicle
what do we know about stem cell niches in central nervous system?
in the brain, dont really know much about them/where they are or what they do
what are stem cells called in the muscle? what do we know about them?
- satellite cells
- not very prone to differentiating
what do we know about stem cell niches in the gut?
- in epithelium
- found in the crypt
- replaced frequently
what do we know about molecular pathways to do with stem cells?
- there are many pathways and modulation of growth factors that are involved in determining stem cell fate
- depending on the stem cell niche you want you need different factors
- you need activation of a specific pathway which will then give you the cell
what do we know about the reactivation of stem cells?
the most potent event promoting adult stems self-renewal and differentiation is TISSUE DAMAGE, to ultimately promote the repair of the tissue and re- establish of tissue homeostasis
what are embryonic stem cells?
- derived from donated IVF embyos
- can be grown indefinitely in the lab in an unspecialised state
- they retain the ability to specialise into many different tissue types- known as pluripotent
- can restore function in animal models following transplantation
cloning for agricultural purposes?
reproducing the best breed
- disease resistant
- suitability to climate
- quality body type
- fertility
- market preference
- food?
therapeutic role of stem cells?
regenerative vet med
- treatment of musculoskeletal injuries in horses and dogs
- preservation of endangered species
- generation of transgenic animals as biomedical models
induced pluripotent stem cells
- starting cells from donor tissue can be induced to change gene expression resulting in pluripotent stem cells
can create stem cells directly from a patient for research