Stem cells

Question 1

Stem Cell

Answer 1

Cells that have the ability to self renew and to give rise to cells that can differentiate.

Question 2

Totipotent

Answer 2

Least determined, capable of giving rise to any cell type

Question 3

Pluripotent

Answer 3

Capable of giving rise to many cells types

Question 4

Multipotent

Answer 4

Make more than one cell type in a closely related family

Question 5

Unipotent

Answer 5

Produce one differentiated cell type

Question 6

Progenitor cells

Answer 6

Can differentiate into multiple cell types, but can only renew a limited number of times. Transient

Question 7

Stem cell

Answer 7

Can divide indefinitely and generate specified cells

Question 8

ES cells

Answer 8

Embryonic Stem Cells
Pluripotent
ICM derived

Question 9

Adult Stem Cells

Answer 9

Multipotent cells Found in adult tissues, thought to be involved in maintaining tissue homeostasis of providing cells for naturally regenerative organs (skin, blood, hair…)

Question 10

Induced Pluripotent stem cells (iPSCs)

Answer 10

Adult cells that have been converted to cells with the pluripotency of embryonic stem cells

Question 11

Stem cell niche hypothesis

Answer 11

A special microenvironment regulates stem cell self-renewal and survival and the differentiation of the progeny that leave the niche.

Question 12

Stem cell niche hypothesis
Signaling factors

Answer 12

Keep cells alive and in multipotent state

Question 13

Stem cell niche hypothesis
Adherence factors

Answer 13

Keep cells in the microenvironment

Question 14

Stem cell niche hypothesis
Asymmetric Division

Answer 14

Positions daughter cells with respect to niche

Question 15

Fly ovarian stem cell niche
Adherence factor

Answer 15

E-cadherin keeps 1 daughter cell in niche

Question 16

Fly ovarian stem cell niche
ECM

Answer 16

Acts as a localized signal
Extracellular matrix molecules keep BMPs close to the source

Question 17

Fly ovarian stem cell niche
Cap cells

Answer 17

Cap cells secrete Bone Morphogenic Proteins (BMPs) that bind to receptors on the surface of GSCs.
BMP signal is sent to GSC nucleus
Bam is repressed - differentiation is prevented

Question 18

Fly ovarian stem cell niche
GSCs

Answer 18

Germline stem cells are in a niche at the tip of each ovariole, where they are in direct contact with cap cells.

Question 19

Fly ovarian stem cell niche
Mitotic spindle

Answer 19

The cell divides perpendicular to the stem cells so that one cell receives signals to retain identity while the other is displaced.

Question 20

Fly ovarian stem cell niche
BAM LOF mutation

Answer 20

With no bam, there is no renewal and there is a bag of marbles mutation.

Question 21

Small intestinal epithelium
Crypt base

Answer 21

Crypts contain intestinal stem cells that produce new cells to replace the old cells in villi.
Crypt base contains ISCs called CBCCs

Question 22

Small intestinal epithelium
Transition amplifying zone

Answer 22

Expands pool of cells created by ISCs to ensure a sufficient supply of differentiated cells

Question 23

Small intestinal epithelium
Intestinal lumen - paneth cells

Answer 23

Paneth cells secrete EGF and Wnt 3a to regulate CBCC symmetrical division.

Question 24

Small intestinal epithelium
Stroma signaling

Answer 24

The stroma has a gradient Wnt 2b and R-spondin which is necessary for the survival and. proliferation of CBCCs

Question 25

CBCCs

Answer 25

crypt base columnar cells Characterized by Lgr5

Question 26

Paneth cell

Answer 26

Secrete Wnt 3a and R-spondin which stimulates the proliferation of CBCCs

Question 27

Wnt/ BMP gradient

Answer 27

WNT - strong at the base of the crypt, maintains stem cell populations (Wnt 2b, respondin, noggin) BMP - Highest in villi region, important for differentiation.

Question 28

Cre system

Answer 28

Cre: bacteriophage that has a recombinase which recognizes lox sites Lox: Unique 34 bp DNA sequence that gets removed by Cre

Question 29

Tests of Stemness

Answer 29

1. iPSCs can differentiate in vitro 2. Teratoma Asso in vivo 3. Mouse embryo cimera

Question 30

Induced pluripotency

Answer 30

IPSCs Differentiated cells can revert to a more plastic state Using viral vectors to revert potency

Question 31

First demonstration of potency reversal

Answer 31

Takahashi/Yamanaka 1. compiled a list of pluripotency factors - factors that promote pluripotency : Oct4, Sox2, Nanog 2. Made skin cells with an Fbx15p:b-georeporter and infected cells with pools of the factors.

Question 32

Fbx15 : B-georeporter

Answer 32

Fbx15: on in embryo and ES, off in differentiated cells B-geo: blue reporter

Question 33

Reporter fusion approach

Answer 33

Finding blue cells after infecting cells with pools of viruses expressing pluripotency factors

Question 34

Organoid

Answer 34

3D tissue structures generated from iPSCs, which self-organize in vitro and exhibit some of the key features of eh represented organ