Stem Cells Flashcards
3 Stages of cells
Stem cell
Transit-amplyfing cell
Differentiated cell
Stem cell
Cell that can continuously produce unaltered progeny cells (self-renewal) and also has ability to produce progeny cells that have different more restricted properties (specialization)
Transit-amplifyng cell
Proliferative stem-cell progeny fated for differentiation (cells can proliferate but not forever)
Differentiated cells
Cells which make necessary functions
progenitor cells
stem cells and transit amplifying cells
Generic term for any dividing cell w/ capacity to differentiate; includes putative stem cells which have not yet demonstrated self-renewal
Main properties of stem cells
- long term self-renewal
- increased proliferative potential (can proliferate alot)
- capacity to multilineage differentiation (differentiation -> different lineages)
- multi-drug resistnat (need protection bc immature/ developing so resistant)
- Telomerase expression (higher telomerase lets cells proliferate)
embryonic stem cells
pluripotent stem-cell lines derived from early embryos b4 formation of tissue germ layers
adult (tissue) stem cells
derived from or resident in fetal or adult tissue w/ potency limited to cells of that tissue; these cells sustain turnover and repair throughout life in some tissues (present all the time in adult and embryo, maintain integrity of who organism)
Degrees of potency
Totipotent -> pluripotent -> multipotent -> oligopotent -> unipotent
totipotent
sufficient to form entire organism (can produce everything during formation) ex zygote, plant meristem cells
pluripotent
able to form all bodies cell lineages including germ cells and some or all extraembryonic cell types (ex embryonic stem cells)
Multipotent
can form multiple lineages that constitute an entire tissue or tissues (ex hematopoietic stem cells)
* can’t do all 3 germ layers
oligopotent
able to form 2 or more lineages with in a tissue; ex neural stem cell that creates subset of neurons in brain
unipotent
forms single lineage (spermatogonial stem cells)
Stem cell hierarchy
Totipotent Zygone Pluripotent Blastocyst (inner cell mass -> embryonic stem cells -> germ layers) (also primordial germ cells -> embryonic germ cells) Multipottent (CANT do all 3 germ layers( Progenitor organs
ESC
embryonic stem cells; harnest 2-3 days mouse can culture and grow in lab or can transfer to adult mouse
ECC
embryonic carcinoma cells, will reduce tumors; harvest 3-7 days mouse
EGC
embryonic germ cells; harvest 9-13 days mouse
Chimeric mice
test embryonic stem cell potential by generation of chimeric mice followed by germ line transmission (put stem cells from gray mouse and black mouse in blastocyst and alter embryo and end up with chimeric adult mouse with cells from 2 mouse strains should make grey (unicolor) and black (unicolor) offspring with black mouse
Shows embryonic stem cells can -> complete mouse
Human pluripotent embryonic stem cells
derived from in vitro cultured cells of inner cell mass in blastocyst after fertilization (day 5-7)