Embryonic Leucine Promotes Early Postnatal Growth via mTOR Signalling in Japanese Quails

Area of Science:

• Developmental biology
• Nutritional science
• Avian physiology

Background:

• Embryonic nutrition significantly impacts postnatal development and growth.
• Mechanisms linking nutrient sensing pathways to avian growth are not fully understood.
• Amino acids are potential regulators of growth via nutrient-sensing pathways like IGF-1/mTOR.

Purpose of the Study:

• To investigate the effects of embryonic leucine on gene expression and phenotypic growth in Japanese quails.
• To elucidate the role of the IGF-1/mTOR pathway in leucine-mediated avian growth.
• To explore embryonic amino acid supplementation as a strategy for enhancing poultry growth.

Main Methods:

• Japanese quail eggs were injected with leucine or saline on day 10 of incubation.
• Hatching success and early growth parameters were monitored.
• Post-hatching body mass, organ lengths, and hepatic gene expression (IGF1, IGF1R, mTOR, RPS6K1, FOXO1) were analyzed.

Main Results:

• Embryonic leucine treatment did not affect hatching success or size at hatching.
• Leucine-treated quails exhibited significantly increased body mass and organ lengths from 3 to 21 days post-hatching.
• Hepatic expression of IGF1, IGF1R, mTOR, and RPS6K1 was upregulated, while FOXO1 remained unchanged.

Conclusions:

• Embryonic leucine supplementation can induce developmental programming, promoting postnatal growth in Japanese quails.
• The IGF-1/mTOR nutrient-sensing pathway is involved in mediating the growth-promoting effects of embryonic leucine.
• Embryonic amino acid availability is a critical factor for optimizing avian growth and performance.