Term
| Secondary Organizers (AP) |
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Definition
- anterior neural ridge (ANR) - secretes FGFs
- zona limtans intrathalamica (ZLI) - diencephalon, secretes Shh
- isthmic organizer (IsO) - between mid+hindbrain, secretes Fgf8[image]
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Term
| Secondary Organizers (DV) |
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Definition
roof plate (RP) - dorsal BMPs and Wnts
floor plate (FP) - ventral Shh |
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Term
| ANR (requires, expresses) |
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Definition
| requires AVE, expresses Fgf8, induces rostralness and regulates AP polarity later |
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Term
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Definition
inhibits transcription factors with anterior low-posterior high gradients (promotes anterior character)
**controls gene expression network**
[image] |
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Term
| IsO: midbrain-hindbrain border |
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Definition
expresses Fgf8
depends on repressive interaction of Otx2 and Gbx2
will induce midbrain/cerebellum if grafted
Fgf8 helps with patterning again |
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Term
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Definition
right in front of the thalamus
critical for AP patterning of the thalamus
produces Shh |
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Term
| What does the notochord control? |
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Definition
the DV polarity of the neural tube (floor plate and motor neurons)
[image]
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Term
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Definition
the ventral identity of the neural tube by graded signaling, antagonizing BMP to define DV
[image] |
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Term
| what regulates the expression of Hox genes? |
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Definition
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Term
| how is the hindbrain divided? |
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Definition
| seven rhombomeres with separate groups of cells that take on specific characteristics like cranial nerves, hox genes regulate the segmental identities |
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Term
| Rostral brain segmentation with Shh help defining AP axis |
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Definition
Diencephalon: prosomeres 1-3 (P1, P2, P3): pretectum, thalamus, prethalamus
Secondary prosencephalon: telencephalon (cortex, striatum, etc.), hypothalamus |
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Term
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Definition
- AP axis induced early
- organizer and mesodermal derivatives: neural induction (BMP inhibition) and anterior fate (Wnt inhibition), AVE antagonizes caudalizing factors (Fgf, RA, Wnt) from primitive streak--> A-P halves
- Secondary organizers formed and signal ino smaller domains of cells, mediated by transcription factors
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Term
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Definition
| increased expression of dorsal (cortical) markers |
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