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Cell Fate II
n/a
21
Biology
Undergraduate 4
11/08/2013

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Cards

Term
for the environment to play a part in determining cell fate, what is necessary?
Definition
cell division
Term
True or false: change in progenitor cell competence can be reversed
Definition
false; it's unidirectional
Term
where do differences in cell characteristics come from?
Definition

differential expression in sets of genes, leading to differing sets of proteins via transcription factors which can promote or repress specific gene expression

 

therefor, mainly expression of certain transcription factors

Term
what can expression of a transcription factor define?
Definition

Anything, broad or narrow, e.g.:

  • developing nervous system (Sox2)
  • developing retina (Pax6)
  • developing rod cells (NrI)

 

Term
beta helix-loop-helix (bHLH) transcription factors
Definition
  • dimer
  • bind E-box (regulatory neuronal differentiation region)
  • functional when bound between A bHLH and B bHLH[image]
Term
proneural bHLH
Definition
  • Class B: Ash1, Ath1, Ath5, Nrg1, 2, and 3
  • misexpression makes progenitor cells differentiate
  • gene knockout can lead to a lack of specific neuronal types developing
Term
seven retinal cell types each determined by ___
Definition
2-7 specific transcription factors (ganglion, horizontal, amacrine, con, rod, bipolar, muller)
Term
Notch and bHLH interaction
Definition
bHLH proneural factor expression-->Delta (Notch ligand)-->Notch activation represses expression of bHLH proneural factors-->delayed differentiation
Term
as a cell differentiates, transcription factors ___
Definition
expressed change; different ones direct different stages of differentiation
Term
inducing factors
Definition
promote expression of specific transcription factors
Term
aorta ___ -->induces ___ expression (bHLH)-->become sympathetic ganglion neurons (from neural crest)
Definition
Term

BMP2-->|Ash1-->___-->___ and ___

 

Definition

Phox2

tyrosine hydroxylase

dopamine B hydroxylase

Term

concentrations of ___ and ___ determine which transcription factors are expressed in the DV axis of dpinal cord

 

Each DV level has its own combination of ___, which determines which cell types develop there

Definition

Shh and BMPs

transcription factors

Term
Ath1 is a ___ that induces ___ with the help of ___
Definition

trancription factor

dl1

external factors

Term
microRNA (MiRNA)
Definition
non-coding cleaved pieces of RNA that hybridize to mRNA and block translation or make them degrade, most found in developmentally regulated brain
Term
MiRNAs cleaved by ___, without which ___
Definition
Dicer; astrocyte genesis reduced and oligodendrocyte genesis eliminated
Term
neural progenitor cells maintained by
Definition
  • REST (repressor element silencing factor)
  • RNA polymerase II CTDSP (c-terminal domain small phosphatase)
Term
REST/CTDSP action
Definition

represses expression of RNA polymerase II, which normally promotes t.f. expression towards neuronal differentiation

 

blocked by miRNAs

Term
compare neural stem cell with neuronal cell
Definition
[image]
Term
cell-cell interactions
Definition
can influence the final phenotype of a cell late in development (e.g. target tissue specifying transmitter phenotype)
Term

sequential steps in the restriction of possible fates are controlled by different mechanisms:

early steps

mid steps

final steps

Definition
  • early: through blastula stage: asymmetric maternal mRNA in cell division
  • mid: secrete inducing factors over large area in gradients (released in one cell affects nearby cell), concentrations determine effects (sum of factors)
  • final: choose from remaining possible fates by cell-cell interaction in environment
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