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)
