Flashcards in 259b stem cells Deck (15):
stem cell traits
self-renewal - regenerates itself
potency - can give rise to different types of cells
asymmetric vs symmetric stem cell division
asymmetric is one identical daughter cell and one differentiated cell
symmetric is two identical stem cells
types of stem cells
toti - zygote
pluripotent - ES, blastocysts (ICM) from 5 day old embryo, give rise to most tissues, adult stem cells
multipotent - HSC, committed to cells with a specific fxn
where do stem cells come from?
ICM of blastocyst
patient specific ES cells (cloning), nuclear reprogramming and problems with reproductive cloning?
make ES with patients own DNA
nuclear reprogramming: remove DNA from egg, inject DNA from donor skin cells, coax into developing
problems: nuclear cloning is not efficient, doesn't product a normal individual when used in reproduction
therapeutic nuclear cloning
goal is to make compatible ES for therapy by fixing mutation (either from unaffected tissue for somatic mutation OR fixing bad gene for germline mutation)
use blood cells and manipulate into other cell types (change from multipotent --> pluripotent)
iPS (induced pluripotent stem cell)
take a differentiated cell and revert to a stem cell
use fibroblasts and give embryonic genes or acidic environment --> pluripotent stem cells
what is the danger of giving patients undifferentiated stem cells?
can form tumors (teratomas)
autologous vs allogeneic
autologous - same person
allogeneic - different people
ability of tissue-restricted stem cell (adult stem cell) to give rise to differentiated cell types of other tissue types
formation of cellular components in blood
Fetal erythropoiesis occurs in:
Yolk sac (3–8 weeks)
Liver (6 weeks–birth)
Spleen (10–28 weeks)
Bone marrow (18 weeks to adult)
Young Liver Synthesizes Blood
hemangioblast are early RBC stem cell
HSC are derived from hemogenic endothelium
**both are from mesoderm origin**
Fetal hemoglobin (HbF) = α2γ2.
Adult hemoglobin (HbA) = α2β2
From fetal to adult hemoglobin:
Alpha Always; Gamma Goes, Becomes Beta.
HbF has higher affinity for oxygen due to less avid binding of 2,3-BPG. This allows HbF to extract oxygen from (HbA) maternal hemoglobin across the placenta.
what does common myeloid progenitor come from? what does it make?
multipotent progenitor (From HSC)
RBCs, monocytes, granulocytes, platelets