Early life nutrient restriction affects hypothalamic-pituitary-interrenal axis gene expression in a diet...

Area of Science:

• Endocrinology
• Developmental Biology
• Ecology

Background:

• Early life stress, including nutrient restriction, can have lasting effects on an organism's physiology and behavior.
• The hypothalamic-pituitary-adrenal (HPA) axis, crucial for stress response, is sensitive to early life conditions.
• Dietary context may influence how early life nutrient stress affects later life HPA axis regulation.

Purpose of the Study:

• To investigate whether carryover effects of early life nutrient restriction on HPA/HPI axis regulation differ based on diet type.
• To examine the impact of larval diet quality on juvenile HPA axis gene expression and body fat in plains spadefoot toads.

Main Methods:

• Experimentally manipulated larval nutrient restriction in plains spadefoot toads (Spea bombifrons) fed either detritus or shrimp diets.
• Measured juvenile brain gene expression of corticotropin-releasing hormone and glucocorticoid/mineralocorticoid receptors.
• Assessed juvenile body fat levels post-metamorphosis.

Main Results:

• Larval nutrient restriction reduced expression of key HPA axis regulators (corticotropin-releasing hormone, glucocorticoid receptors, mineralocorticoid receptors) in juveniles, but only when larvae consumed shrimp.
• Juvenile body fat levels were increased by larval nutrient restriction, irrespective of diet type.
• These findings suggest diet-specific carryover effects of early life nutrient stress on HPA axis regulation.

Conclusions:

• HPA/HPI axis responses to nutrient restriction are significantly influenced by the type of diet consumed during early development.
• Diet-dependent regulation of the HPA axis may contribute to developmental or evolutionary adaptations to varying environmental conditions.
• Understanding these diet-specific effects is crucial for predicting long-term consequences of early life stress.