259b stem cells Flashcards Preview

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Flashcards in 259b stem cells Deck (15):
1

stem cell traits

self-renewal - regenerates itself

potency - can give rise to different types of cells

2

asymmetric vs symmetric stem cell division

asymmetric is one identical daughter cell and one differentiated cell

symmetric is two identical stem cells

3

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

4

where do stem cells come from?

ICM of blastocyst

5

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

6

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)

7

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

8

what is the danger of giving patients undifferentiated stem cells?

can form tumors (teratomas)

9

autologous vs allogeneic

autologous - same person

allogeneic - different people

10

plasticity

ability of tissue-restricted stem cell (adult stem cell) to give rise to differentiated cell types of other tissue types

11

hematopoiesis

formation of cellular components in blood

12

fetal hematopoiesis

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**

13

hemoglobin development

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.

14

what does common myeloid progenitor come from? what does it make?

multipotent progenitor (From HSC)

RBCs, monocytes, granulocytes, platelets

15

what does common lymphoid progenitor come from? what does it make?

multipotent progenitor (From HSC)

B/T/NK cells