Circadian rhythm disruption linked to skeletal muscle dysfunction in the Mexican Cavefish

Area of Science:

• * Chronobiology
• * Molecular Biology
• * Physiology

Background:

• * Circadian clocks in peripheral tissues, particularly skeletal muscle, are crucial for normal physiological function.
• * Disruptions to skeletal muscle circadian clocks are linked to conditions like insulin resistance and muscle weakness.
• * Mexican cavefish (Astyanax mexicanus) possess a disrupted central circadian clock, prompting investigation into their peripheral clock mechanisms.

Purpose of the Study:

• * To investigate the functional status of the circadian clock in the skeletal muscle of Mexican cavefish.
• * To determine if alterations in peripheral clocks contribute to observed muscle phenotypes in cavefish.
• * To identify specific genes and molecular pathways affected by clock disruption in cavefish skeletal muscle.

Main Methods:

• * Analysis of gene expression rhythmicity in skeletal muscle tissue of Mexican cavefish.
• * Assessment of protein catabolism patterns during nocturnal periods.
• * Comparative analysis of gene functions related to human metabolic disorders.

Main Results:

• * Demonstrated a significant loss of circadian clock function in the skeletal muscle of Mexican cavefish.
• * Observed reduced rhythmicity in a large number of genes within the skeletal muscle.
• * Identified disrupted nocturnal protein catabolism and identified genes linked to human metabolic dysfunction.

Conclusions:

• * The Mexican cavefish exhibits impaired skeletal muscle circadian clock function, independent of central clock disruption.
• * This peripheral clock dysfunction contributes to molecular and physiological alterations in skeletal muscle.
• * The identified genes offer insights into the molecular basis of muscle weakness and metabolic dysfunction in cavefish and potentially humans.