cell type or characteristics of a cell

(position, form, and function)

competence,

specified,

determined/committed,

differentiated

has been exposed to inducers, my be leaning towards a certain development path, but environment changes can stil have an effect on the fate

totipotent, pluripotent, unipotent

sequentially restricts possible fates

intrinsic-genetic/inherited program

extrinsic cue- environmental features a cell can respond to; induces intrinsic changes

sets of cells where each set leads to certain cell types.

destroying a whole founder group leads to an absence of future structures, but destroying a portion of them only has minimal effects

(apparent in 512 cell blastula)

domain of the nervous system

(but not just position)

Anterior-posterior factor concentrations like FGF and RA

(fibroblast growth factor and retinoic acid)

notochord-->floor plate

[image]

What happens if we remove the notochord early?

Transplant second notochord?

No floor plate or motor neurons

second floor plate, more motor neurons

[image]

What happens if you...

• implant cells expressing Shh next to the neural tube?
• use antibodies to Shh?
• have a high/low [Shh]?

• induced floor plate and motor neurons
• notochord blocked from inducing ventral structures
• induce floor plate/induce motor neurons

• Patched normally _____
• When _(ligand)__ binds to Patched, what happens?

• inhibits smoothened
• Shh, Smoothened activated, which activates Gli transcription factors[image]

[BMP] and [Shh] have opposite gradients, which match up with specific A-P positions, and segments of these areas become the different domains

[image]

• ___ initiates differentiation
• ___ results in ganglion and cone cell diff.
• ___ results in rod, bipolar, and Muller glial cell diff.
• as progenitor cell competence changes, ___

• progenitor cell dissociation
• young retinal progenitor cell dissociation
• old retinal progenitor cell dissociation
• production of early cell types stops and production of later cell types starts[image]

production of more of the same cell type

production of other cell types

increased development of that cell type (more of that cell type being added over time)

same for crest cells that would become DRG; if it's not taken care of already, the environment makes up for it

change the coompetence of neighboring progenitor cells

(as cells differentiate, they release signals that promote development moving forward)

glial cells

neural crest-->DRG-->glial cells

• glial cells ___ and secrete ___
• migrating crest cells ___

• aggregate as a ganglion, beginning to differentiate, secrete Neuregulin-1 (Nrg-1)
• express receptor for Nrg-1

• crest cells alone in culture --> _____
• add Nrg-1--> ____
• block Nrg-1--> ____

• neurons AND glia
• all glia
• all neurons[image]

In cultures of CNS progenitor cells, describe behavior of:

• cytokines CT-1 or CNTF
• PDGF

• blocks neurogenesis and promotes astrocyte genesis
• promotes oligodendrocyte genesis[image]

Describe function of CT-1 and CNTF on astrocyte specific proteins like GFAP and S100

They bind to cell surface receptors which activate STAT3 by phosphorylation, and the active STAT3 binds astrocyte protein-promoters, leading to astrocyte production.

If the promoters are methylated (early development), STAT3 can't bind, so neurons generated anyway.

[image]