Cell signalling pathways roles Flashcards
Hedgehog (SHH) is involved in…
separation of the single eye field into 2 bilateral fields.
Neuronal tube development.
Bone development, cell fate in the spinal cord, development of digits
Hedgehog signalling defects can cause…
Cyclopia (single eye). This is caused by SHH not separating the single eye field during development. The nose either does not develop or is replaced by a non-functioning proboscis.
This is a congenital disease (present from birth)
Hedgehog discovery
WT flies have denticle bands that are spaced out. Hedgehog mutants have a denticle lawn due to denticles not spacing out, therefore giving flies hedgehog-like spikes.
Notch is involved in…
Neuronal function and development.
Stabilisation of arterial endothelial fate and angiogenesis.
Binary fate decisions of the cells in the gut.
Expansion of the hematopoietic stem cell compartment.
Regulation of cell-fate in mammary glands.
Notch signalling defects can cause…
T-ALL (T-cell acute lymphoblastic leukaemia) - where too many T-cell lymphoblasts are found.
Alagille syndrome - mutation in Jagged1 (JAG1 gene). Autosomal dominant disorder that causes developmental abnormalities in the liver, heart, eye and skeleton.
Spondylocostal Dysostosis - causes vertebral segmentation defects which are associated with rib defects such as fusions and deletions.
Wnt is involved in…
Cell fate specification in the spinal cord, stem cells and gut development.
Wnt signalling defects can cause…
Cancer - Wnt is the proto-oncogene for breast cancer in mice.
Involved in the development of benign and malignant breast tumors. The change is B-catenin can be measured in cancer.
FGF is involved in…
Angiogenesis and wound healing, embryonic development, key in proliferation and differentiation of cells.
Stem cells, limb bud development and segmentation.
TGF-Beta is involved in…
Bone development
TGF-Beta signalling related disease
Martan Syndrome
- Genetic disorder of connective tissue.
- Long limbs, unusually tall and long thin fingers.
- Related to the gene FBN1 which encodes the connective protein, fibrillin 1 which provide strucutral support. FBN1 binds TGF-Beta, TGFB has a deleterious effect on vascular smooth muscle development and ECM integrity when overly active. Therefor the excessive TGFB can weaken lungs, heart valves and aorta.
