Transcriptomic signals of mitochondrial dysfunction and OXPHOS dynamics in fast-growth chicken

Area of Science:

• Comparative genomics
• Avian physiology
• Aging research

Background:

• Birds possess adaptations to manage oxidative stress, with lifespan inversely related to oxidative damage.
• Mitochondrial function is key to cellular health, but age-related mitochondrial gene expression and oxidative phosphorylation (OXPHOS) patterns in birds are not well understood.
• Domestic chickens, selected for rapid growth, provide a model to study oxidative stress, growth rate, and aging.

Purpose of the Study:

• To investigate age-related patterns of mitochondrial gene expression and OXPHOS in fast- and slow-growing chicken breeds.
• To understand the relationship between oxidative homeostasis, growth rate, and aging in birds.

Main Methods:

• Compared pectoralis muscle gene expression in fast- and slow-growing chickens at 11 and 42 days old using RNAseq.
• Analyzed transcriptomic data to identify differences in mitochondrial function and OXPHOS performance.

Main Results:

• Fast-growing chickens exhibited mitochondrial dysfunction and reduced OXPHOS in breast muscle compared to slow-growing breeds.
• Transcriptomic data revealed reduced OXPHOS performance in young fast-growing broilers, which further declined by 42 days.
• Sirtuin signaling and NRF2-dependent oxidative stress responses were implicated in oxidative damage progression in fast-growing chickens.

Conclusions:

• Rapid growth in chickens places significant stress on oxidative performance, overwhelming the OXPHOS system.
• There are inherent constraints on oxidative capacity that limit sustained fast growth at high metabolic rates in modern broiler chickens.
• Findings suggest that early-life rapid growth impacts long-term mitochondrial health and oxidative performance.