Kidney development

Question 1

Interactions between which 2 structures?

Answer 1

1. Ureteric bud

2. Metanephric mesenchyme

Question 2

What does the ureteric bud induce the nephrogenic mesenchyme to do?

Answer 2

Condense around the bud

Undergo a mesenchymal-to-epithelial transition- forming renal epithelium- then renal vesicles

Question 3

What does the renal vesicle differentiate in to?

Answer 3

The nephron-
proximal end: provides local signals for angiogenesis
distal ends: fuses with collecting duct by selective apoptosis

Question 4

What does the uteric bud undergo in order to create 10^6 nephrons?

Answer 4

Branching morphogensis

Question 5

How many nephrons are there per collecting duct?

Answer 5

6 nephrons

Question 6

What are the key steps in branching morphogenesis?

Answer 6

1. Proliferation and outgrowth of bud tip cells
2. Arrest in proliferation resulting in flattening
3. Continued proliferation of lateral tip cells

Question 7

What is the signal from the mesenchymal cells? And what is the receptor found on the bud?

Answer 7

GDNF signals to the Ret receptor

Question 8

Where are stem like cells in the kidney found?

Answer 8

Ureteric bud and metanephric mesenchyme

Question 9

What does Six2 do?

Answer 9

Six2 is a transcription factor that is expressed in nephron stem cells- forms the nephron and all the cells within it

Question 10

What forms the ureteric bud and metanephric mesenchyme?

Answer 10

Intermediate mesenchyme undergoes a m-to-e transition to form 2 structures:

1. Nephric duct- forms a lumen and gives rise to the ureteric bud
2. Nephric cord- gives rise to the metanephric mesenchyme

Question 11

What happens in attempts to form the definitive kidney?

Answer 11

Pronephric tubules degenerate
Mesonephric tubules attracts a blood supply- tubule forms a capsule around a capillary tuft- allowing for blood filtration
Mesonephros then largely degenerates
Metanephric kidney= finally induced