Caveolae Protect Notochord Cells against Catastrophic Mechanical Failure during Development

Area of Science:

• Developmental Biology
• Cell Biology
• Biomechanics

Background:

• The embryonic notochord provides skeletal support for spine formation and facilitates locomotion in chordates.
• Notochords experience significant mechanical forces during body movement.
• Caveolae, plasma membrane invaginations, are hypothesized to protect cells under mechanical stress.

Purpose of the Study:

• To investigate the role of caveolae in notochord mechanoprotection.
• To determine the function of Cavin1b, a protein essential for caveola formation, in the embryonic notochord.

Main Methods:

• CRISPR/Cas9 gene editing was used to create a zebrafish mutant lacking Cavin1b (cavin1b-/-).
• Locomotor capacity, notochord morphology, and cell viability were assessed in mutant zebrafish.
• Mechanical stress assays were employed to correlate lesion severity with locomotion and observe in vivo caveolae dynamics.

Main Results:

• cavin1b-/- zebrafish exhibited reduced locomotion and severe notochord lesions with cellular damage.
• Notochord diameter and body length were reduced, but mutants were viable and recovered.
• Lesion severity directly correlated with locomotion, and caveolae morphology changed in response to mechanical stress.

Conclusions:

• Caveolae are crucial for protecting the embryonic notochord from mechanical damage during locomotion.
• Cavin1b is essential for caveola formation and subsequent cellular mechanoprotection in the notochord.
• This study provides real-time evidence of caveolae mediating cellular mechanoprotection in vivo.