Commitment to cell differentiation Flashcards
What causes a cell to commit to a morphogenesis change?
Gene expression and signalling
What do the specific changes to a cell depend on?
Transcriptional environment
What are the two levels of commitment?
Specification and determination
What is specification?
Cells are directed to commit to a particular fate, told what the next steps are
What causes specification?
Induction and differential gene expression
What is autonomous specification?
The signal to become specified are maternal signals and are already present in the egg at the time of fertilization in the form of mRNA and proteins
What is conditional specification?
The cell responds to signals from the outside and activates genes in response to those signals
What is syncytial specification?
All the cells in a group are joined and share common cytoplasm, and they share signals that way
What is determination?
A highly committed cell state where the cell will continue on its current path no matter what else it is told
What is a morphogen?
Signals that induce morphogenesis and differentiation
Why are cells specified in a concentration dependent manner?
How close the cells are to the source of the signal will affect how much of a morphogen they get, and thus their differentiation
How can cells differentiate into different cell types in response to the same signal?
Concentration dependent. It may take a certain amount of a morphogen to reach a threshold to cause differentiation into a neuron (ex.), but if the cell doesn’t reach that threshold it becomes a skin cell (ex.)
What is the order of events that leads to morphogenesis, starting with a signal?
- Signal/induction
- Specification
- Differential gene expression
- Determination
- Morphogenesis
