Developmental Bio Exam 3 - Part 2 (Stem Cell Concept)

stem cell

undifferentiated cell with self-renewing cell division

1. another stem cell

2. cell which will differentiate

when stem cells divide they produce these 2 cells

totipotent

can form any other type of cell in the organism; limited to the zygote

pluripotent

able to form many different types of cells but are limited in some manner or another

multipotent

tissue-specific stem cells (ex. satellite cells)

progenitor cells

will become specific type of cell (ex. can only form a neural cell)

precursor cells

have begun the process of terminal differentiationdiff

differentiated cells

functional, nonmitotic cells; performing the function of the cell they differentiated into and have stopped dividing to maintain that

asymmetric division

lack of uniform cytoplasm where one cell contains signal and the other doesn’t

symmetric division

creates a microenvironment that allow stem cells to retain their identity until they leave that microenvironment

rodent incisors

example of symmetric division

satellite cells

muscle stem cells are known as

scar tissue

when the muscle stem cell process is not completely correct, you get…

1. inflammation

2. activation of satellite cells

3. proliferation

4. differentiation

5. maturation

muscle repair steps

white blood cells

during inflammation, these cells are recruited to bring growth factors and start the repair process

myosin and actin

during satellite cell maturation, the expression of these are increased

negative TGF-Beta factors

what will turn the satellite cell system off

produce extreme excess of muscle

the satellite cell process must be managed and turned off so as to not…

limb development

formation of the somites begins the process of…

T-Box proteins

transcription factors that initiate the formation of the limb bud

Tbx5

activates forelimb development

Tbx4

initiates hindlimb development

proximal-distal

the new axis formed during limb formation

apical ectodermal ridge (AER)

the limb bud forms from the…

limb development stops

removal of AER =

limb is duplicated

extra AER =

wing grows into a leg

leg mesenchyme in AER area =

AER regresses and limb development stops

non-limb mesenchyme in AER area =

normal development

AER replaced by FGF bead =

temporal

the progress zone model is…

spatial

the early allocation and progenitor expansion model is…

morphogen interaction

the reaction diffusion model is a…

Shh

determines A-P axis on the wing

1. determination

2. proliferation

3. cell alignment

4. fusion, differentiation

5. fusion of most remaining myoblasts

6. maturation

6 steps of myogenesis

high presence of muscle cells

lack of myostatin leads to…

intermembranous ossification

mechanism that forms the flat bones

endochondral ossification

formation of the long bones

chondrogenic progenitor cells

cells that will most likely become cartilage but are not at the stage that they couldn’t form something else if needed

Sox9

important marker of transition from compact to proliferating chondrocytes

VEGF

recruits blood vessels to grow in the center of the bonev

vascularization

transition from cartilage to bone (blood supply must be present for ossification to occur)

ECM changes

what causes chondrocytes to begin to die

blood supply

what brings in the new set of stem cells into the developing bone (osteoblasts, osteocytes, and osteoclasts)

at the end of each bone

where the secondary growth centers are

allows for other features to grow at the ends of the bone

secondary growth plate function

spongy bone layer beneath solid bone

osteoclasts are responsible for the…

Wnt

allows for differentiation of bone cells