Lecture 4 - Generation of the difference between embryos (2) Flashcards
How can cells generate differences between themselves? [3]
- Cell communication
- Asymmetric cell division
- Segregation of cytoplasmic determinants
How can cell to cell communication be achieved?
- Diffusion
- Direct contact
- Gap junctions
Give an example of segregation of cytoplasmic determinants.
The segregation of P-granules to the posterior when an egg is fertislised
What is the first cell division in a early embryo?
- AB
- P1
What does the AB divide into?
- AB.a
- AB.p
What does the AB.a divide into?
- AB.ar
- AB.al
What does AB.p divide into?
- AB.pr
- AB.pl
What does P1 divide into?
- P2
- EMS
What does EMS divide into?
- MS
- E
What does P2 divide into?
- P3
- C
What does P3 divide into?
- D
- P4
What is Pie-1 required for?
Germline development
What do mutants in the Par genes effect?
They effect the localisation of Mex-5 and Pie-1
The first [A] divisions of an embryo are symmetric, giving [B] identical cells.
A - 5
B - 32
What is the pattern for the first asymmetric cell divisions in an embryo?
- Cells at bottom continue to divide symmetrically giving somatic cells
- Cells at top divide asymmetrically giving somatic cells and gonidial cells (1:1 ratio)
How is the ABp different from ABa?
It receives a signal from P2
How does the signal from MS affect ABal?
Important for making the pharynx
Why does the signal from MS not affect ABpl?
The signal it received from P2 blinds it to the MS signal
What two proteins affect the signal between P2 and ABp?
- Apx-1
- Glp-1
Where is Glp-1 found?
- ABa
- ABp
Where is Apx-1 found?
In P2
Which one out of Apx-1 and Glp-1 is the receptor?
Glp-1
True or False? The acitvation of pharynx making ABal cells requires both glp-1 and Apx-1.
True
