W10 Stem Cells Flashcards
what are stem cells
unspecialised cells
what do stem cells create as a middle step
intermediate cells
what is lineage in terms of stem cells
number of cell types arising from a stem cell
what is the potency of stem cells
possible routes for a stem cell
where are totipotent cells found
zygotes
blastocytes
placenta
where are pluri/multipotent cells found
embryonic stem cells
how are cell types selected for
turning on and off genes
how do radiation affect human cells
depleted blood and mutations
what is the job of pluripotent stem cells
create all cell types
what are pluripotent stem cells able to do
self renew
what are Morphogens
signalling proteins which make gradients
what are niche cells responsible for
creating microenvironments
what happens when niche cell finds a signal
external polarity causes localization of cell fate determinants will undergo intrinsic asymmetry
what are the 3 types of signals
autocrine
paracrine
systemic
what is a autocrine signal for
signals for cells self
what is a paracrine signal for
signals for neighbouring cells
what is a systemic signals for
signals for other tissue
what secretes signal molecules
ECM (extracellular matrix concentrates)
what’s the job of the intestinal epithelium
regulates water and nutrient absorption
how often does the intestinal epithelium renew
one of the fastest -> 3 to 5 days
what are crypts in the intestinal epithelium for
contains intestinal stem cells and Paneth cells
what type of receptors are found on intestinal crypts
G-protein receptors Lgr5
what type of cell sheds into the lumen of intestines
differentiated cells
how is apoptosis induced in cells
DNA damage signals
lack of growth stimuli
what is flow cytometry and its steps
- identification of adult stell cells
- dissociate tissue of interest into single cells
- label stem cell with fluorescent antibody
in vitro how are isolated cells form
in spheres
in vitro how do you determine stemness of mini gut cells
- isolate crypt
- embed in 3d matrix and use FACS
- use EGF for growth and analysis
what do Epidermal Growth Factor (EFG) do
Promotes cell proliferation
how does a transplantation assay work in-vivo
irradiate tissue then add bone marrow cells from healthy donor
how does cell lineage tracing work
- add visible genetic mark in stem cell
- mark can be activated by specific tissue
- track using a turnover assay
how does nuclear transfer work for reprogramming diffed cells
- use oocytes or somatic cells
- move nucleus into cytoplasm of large cell
- changes in chromatin will occur
how does cell fusion work for reprogramming diffed cells
- cell mass of blastocyst can be used to create ESC (embryonic stem cells)
- 2 cells are fused
- observe how the genomes interact
how does transcription factor induced work for reprogramming diffed cells
- binding of a TF can cause growth of iPS cells
how are iPS created
reprogramming from somatic cells
why are iPS and ES useful for drugs
screening and human disease models
describe nuclear reprogramming of reproductive cloning
- using somatic cells and oocytes using cell fusion
- activate egg cell to turn somatic cell into totipotent cell
what happens during asymmetric division
1 differentiated and 1 undifferentiated cell produced
what is possible with symmetric division
2 un/differentiated cells
what type of division do stem cells undego
symmetric division
what type of cell uses asymmetric division
tissue cells
what is retrospective experimental method for adult stem cell identification
using past models instead of prospective using raw collected data
what are the 2 advantages of adult stem cells
- autologous
- stable
what is a disadvantage of adult stem cells
problems with amplification
what are induced pluripotent stem cells
man made stem cells
