Genetic Foundations of Disease and health Flashcards
Describe Cell Fate
the types of cells this cell will produce (fate can change)
Determination
A cell is determined if it is moved from its original area and IS NOT influenced by the new area
Specification
Cell is removed and develops normally in isolation
Not determined
A cell is moved to a new area and IS influenced by the new area
Lineage
All of the cells born from a single cell
Morphogenesis
The creation of ordered form in development
How do inductive signals relate to embryos and development
An inductive signal will cause the fate of a cell to change
What is a permissive signal
a signal that allows cells to reach developmental potential but do not direct their fate
What is an instructive signal
a signal that tells cells to adopt a new fate
What are examples of 4 long range signals
Hedgehog
TGF beta / BMP
Wnt
FGF
What are two examples of short range membrane bound signals
Notch/Delta
Eph/ephrin
Can the same signal have different effects? If so, how?
The same inductive signal can induce different changes based on receptors, stage of development, other activating or repressing transcription factors, chromatin state, etc…
Notch delta pathway - how do the two cells involve differentiate over time
In the beginning cells both express equal numbers of notch and delta proteins and over time the cells randomly down regulate and upregulate the notch/delta proteins so one has all notch and one is all delta
The delta protein is signaling or receptor
signalling
The notch protein is signaling or receptor
receptor
How does the Notch protein work as a receptor
Upon binding of the delta protein an internal protease cleaves the internal portion of the protein that relocates to the nucleus and where it regulates target gene expression in tandem with Hes B
Activin is a member of what signaling molecule family?
TGF Beta
What is the role of activin?
Activin works to determine cell fate - no activin allows ectoderm cells to become epidermis
small activin results in blood cells, mesenchyme cells
more activin leads to muscle, notochord and a lot of activin results in cardiac cells
The notch pathway involves
Both a transmembrane ligand and transmembrane receptor
Wnt pathway involves
Beta catenin
FGF pathway involves
kinase
TGF pathway involves
Smad’s
The TGF pathway
two peptide receptor that dimerize upon binding the ligand, cross phosphorylation occurs and phosphorylation of the Smad, smad binds a Co-smad which allows for entry to the nucleus
Phosphorylation of the smad causes
a conformational change that reveals a nuclear localization sequence and either activates or inactivates a gene
