Methods in development(Classical approaches)

Question 1

How does descriptive anatomy work in today’s age?

Answer 1

• We can label cellular/subcellular structures with fluorescent tags
• We can follow developmental events over time

Question 2

Why is fate management done?

Answer 2

-Fate management is done to follow cells to see where they end up

Question 3

What does fate management and lineage analysis define?

Answer 3

-They define patterns of cell migration and origins of cells in formed structures

Question 4

What are the fate mapping techniques?

Answer 4

• Mark or label cells so that they can be distinguished later
• Chemical markers
  
  • Vital dyes
  • Radiolabel
  • Carbocyanine dyes
  • Fluorescent dextrans
  • Enzymes
• Genetic markers
  
  • Retroviruses
  • Chimeras
    
    • Transgenics

Question 5

What protein do transgenic zebrafish embryo express?

Answer 5

-Transgenic zebrafish embryos express Kaede

Question 6

What happens to the Kaede protein upon illumination with UV light?

Answer 6

-Upon illumination with UV light, the Kaede protein changes conformation and appears red

Question 7

How does fate mapping retrospectively work?

Answer 7

• All the cells of the embryo are labelled green

- The movie is reversed to view where the cells came from originally.

Question 8

How does the chick quail chimeras work?

Answer 8

• We can graft a small piece of quail embryo in to a chick embryo and this graft of cell will integrate into tissue and will give rise to the structures in a normal way.
• Some proteins that are expressed in quail cells aren’t found in chick cells and we can use specific antibodies that bind to quail cell proteins and we can map their fate
• Another way of detecting quail cells is by looking at the organisation of DNA because they show condensed DNA around their nucleoli.

Question 9

What is a variation of the chimera technique for fate mapping?

Answer 9

-A variation of this technique is dye labelling and grafting so we can use 2 embryos of the same species and one of them will be labelled with a dye. We will graft from the dye labelled embryo and plant it into a host embryo which hasn’t been dyed.