mTOR signalling, embryogenesis and the control of lung development

Area of Science:

• Developmental Biology
• Cellular Biology
• Physiology

Background:

• A nutrient-sensitive regulator of embryonic growth was hypothesized in the early 20th century.
• The mammalian target of rapamycin complexes (mTORC1 and 2) are now known to perform this function.
• mTORC1 and 2 balance nutrient and energy supply during critical embryonic stages.

Purpose of the Study:

• To review the role of mTOR complexes in embryonic development.
• To analyze mTOR's function in organogenesis and tissue growth.
• To demonstrate mTOR's central role in defining organ structural complexity.

Main Methods:

• Review of existing literature on mTOR and embryonic development.
• Synopsis of mTOR's role in embryonic cleavage and stem cell formation.
• Analysis of lung branching morphogenesis as a model system.

Main Results:

• mTORC1 and 2 are essential for embryonic cleavage, stem cell layer formation, and organogenesis.
• These complexes regulate nutrient and energy balance throughout fetal development.
• Lung branching morphogenesis exemplifies mTOR's role in organ structural complexity.

Conclusions:

• mTOR complexes fulfill the criteria for a nutrient-sensitive growth controller.
• mTORC1 and 2 are the likely autocatakinetic centers driving fetal tissue growth.
• This review supports the hypothesis of a nutrient-sensitive regulator in embryonic development.