Green - Stem Cells

Question 1

Stem Cell

Answer 1

Undifferentiated, self renewing cells

Question 2

What are three sources of G_o cells that can proliferate?

Answer 2

Fibroblasts, Endothelial Cells, Liver Epithelial Cells

Question 3

Totipotent

Answer 3

Can form complete organism, present in embryo

Question 4

Pluripotent

Answer 4

Can form many tissue types, but not complete organism;

present in embryo

Question 5

Multipotent

Answer 5

can form different types of cells within an organ, but not different organ or cell type

Present in adult

Ex: Hematapoeitic cells

Question 6

Unipotent

Answer 6

Can form only one type of cell; present in adults

Question 7

Explain stem cell division

Answer 7

One daughter cell remains stem cell, second divides and differentiates. These don’t always have to follow the same path; some will differentiate some will stay at certain points.

Question 8

Transit Amplifying Cells

Answer 8

Rapidly dividing cells between stem cells and full differentiation; represent a point of no return

Question 9

What determines the fate of a daughter stem cell?

Answer 9

Needs of the organism; driven by:

1. Neighboring cell signals
2. Microenvironment of stem cells–niche

Question 10

Hematopoietic Stem Cells

Answer 10

Form red blood cells, platelets, and immune cells

Question 11

What produces the niche in humans?

Answer 11

Liver in late fetal development; bone marrow in adults

Question 12

Where are intestinal stem cells found? How do they differentiate?

Answer 12

Crypt

Divide and differentiate as they move up the villus

Question 13

What is the stem cell of the crypt?

Answer 13

Lgr5+

Question 14

What is the key regulator of stem cells in the intestines?

Answer 14

Wnt protein secreted by niche cells

Question 15

What are the two sources of clinical stem cells?

Answer 15

Embryonic Stem Cells (ES) and Iduced Pluripotent (iPS) Stem Cells

Question 16

What is the source of ES Cells?

What type of stem cells are these?

Answer 16

Inner cell mass in blastocyst

Pluripotent

Question 17

iPS Cells

What type of stem cells are these?

Answer 17

Reprogrammed adult cells

Pluripotent

Question 18

How are ES cells maintained in culture?

Answer 18

Conditioned medium that contains growth factors, taken from irradiated fibroblast cells–can’t divide

Question 19

What are the inhibitory growth factors for ES cells?

What occurs if these are removed

Answer 19

LIF for mouse

bFBF for human cells

ES cells form multicellular aggregates that resemble early embryos–embryoid bodies

Question 20

What regulates pluripotency of ES cells?

Answer 20

Transcriptional Factors

Oct4, Sox2, Nanog

Each binds to own promoter and to other promoters–can activate or repress genes

Question 21

How can you form iPS cells from adult cells?

Answer 21

Add correct transcriptional factors

Oct4

Sox2

Klf4

c-Myc

Question 22

Somatic Nuclear Transfer

Answer 22

Transfer of nucleus from adult cell into unfertilized egg

Question 23

What are two examples of somatic cell nuclear transfer?

Answer 23

GFP mice

Cloned animals (Dolly)

Question 24

What are some medical applications of iPS cells?

Answer 24

Hematopoietic stem cell transplantation

Testing drugs for individual implementation

Therapeutic cloning (healing a patient with their own stem cells)