Term
| for the environment to play a part in determining cell fate, what is necessary? |
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Definition
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Term
| True or false: change in progenitor cell competence can be reversed |
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Definition
| false; it's unidirectional |
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Term
| where do differences in cell characteristics come from? |
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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 |
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Term
| what can expression of a transcription factor define? |
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Definition
Anything, broad or narrow, e.g.:
- developing nervous system (Sox2)
- developing retina (Pax6)
- developing rod cells (NrI)
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Term
| beta helix-loop-helix (bHLH) transcription factors |
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Definition
- dimer
- bind E-box (regulatory neuronal differentiation region)
- functional when bound between A bHLH and B bHLH[image]
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Term
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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
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Term
| seven retinal cell types each determined by ___ |
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Definition
| 2-7 specific transcription factors (ganglion, horizontal, amacrine, con, rod, bipolar, muller) |
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Term
| Notch and bHLH interaction |
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Definition
| bHLH proneural factor expression-->Delta (Notch ligand)-->Notch activation represses expression of bHLH proneural factors-->delayed differentiation |
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Term
| as a cell differentiates, transcription factors ___ |
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Definition
| expressed change; different ones direct different stages of differentiation |
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Term
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Definition
| promote expression of specific transcription factors |
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Term
| aorta ___ -->induces ___ expression (bHLH)-->become sympathetic ganglion neurons (from neural crest) |
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Definition
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Term
BMP2-->|Ash1-->___-->___ and ___
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Definition
Phox2
tyrosine hydroxylase
dopamine B hydroxylase |
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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 |
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Definition
Shh and BMPs
transcription factors |
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Term
| Ath1 is a ___ that induces ___ with the help of ___ |
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Definition
trancription factor
dl1
external factors |
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Term
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Definition
| non-coding cleaved pieces of RNA that hybridize to mRNA and block translation or make them degrade, most found in developmentally regulated brain |
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Term
| MiRNAs cleaved by ___, without which ___ |
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Definition
| Dicer; astrocyte genesis reduced and oligodendrocyte genesis eliminated |
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Term
| neural progenitor cells maintained by |
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Definition
- REST (repressor element silencing factor)
- RNA polymerase II CTDSP (c-terminal domain small phosphatase)
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Term
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Definition
represses expression of RNA polymerase II, which normally promotes t.f. expression towards neuronal differentiation
blocked by miRNAs |
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Term
| compare neural stem cell with neuronal cell |
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Definition
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Term
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Definition
| can influence the final phenotype of a cell late in development (e.g. target tissue specifying transmitter phenotype) |
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Term
sequential steps in the restriction of possible fates are controlled by different mechanisms:
early steps
mid steps
final steps |
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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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