Lung & Liver Development

Question 1

What tissues form from the foregut (ventral) endoderm?

Answer 1

The lung, liver, and pancreas all form from the foregut endoderm during development

Question 2

What induces the development of lung, liver, and pancreas from the foregut endoderm?

Answer 2

• FGF signaling secreted from the cardiac mesoderm induces the development of lung, liver, and pancreas from the foregut endoderm.
• when foregut endoderm is cultured with cardiac mesoderm, liver cells express albumin (liver marker), but not Pdx1 (pancreas marker)

Question 3

How does the presence of FGF signaling impact cell fate during lung and liver development?

Answer 3

• higher levels of FGF signaling induce lung cell fate, intermediate levels induce liver cell fate, and no FGF signaling leads to pancreatic development.
• this indicates that FGF acts as a morphogen, creating a concentration gradient that determines specific cell fates in the developing tissues.

Question 4

What are morphogen gradients and how do they pattern tissues?

Answer 4

-a secreted signaling molecule that can induce three or more different cell fates
- cells in the morphogen gradient turn on specific genes, leading to different cell fates based on the concentration of the morphogen.

Question 5

What is the summary of lung, liver, and pancreas development from the foregut and the role of FGF?

Answer 5

1. Lung, liver, and pancreas cell fates are induced by foregut endoderm, which receives FGF signaling from the cardiac mesoderm.
2. High levels of FGF induce lung cell fate, intermediate levels induce liver cell fate, and absence of FGF induces pancreas development.
3. FGF acts as a morphogen, creating a concentration gradient that influences the specific cell fates in the developing tissues.

Question 6

What is the “French Flag Model” in development?

Answer 6

Concept: Different cell types induced by a signaling gradient.
Example: FGF creates a gradient in foregut endoderm.

Question 7

What happens in the “French Flag Model” during lung and liver development?

Answer 7

High FGF = lung cell fate (red).
Intermediate FGF = liver cell fate (white).
No FGF = pancreas development (blue).

Question 8

What does the “French Flag Model” explain?

Answer 8

How different cell types form in response to varying FGF levels.
Helps understand tissue patterning during embryonic development.