Autophagy is essential for cardiac morphogenesis during vertebrate development

Area of Science:

• Developmental Biology
• Cell Biology
• Genetics

Background:

• Autophagy is an evolutionarily conserved lysosomal degradation pathway vital for eukaryotic differentiation and development.
• Its role in embryonic morphogenesis, particularly during embryogenesis, remains largely unexplored.

Purpose of the Study:

• To investigate the role of autophagy in early vertebrate development and morphogenesis.
• To determine if autophagy is essential for cardiac development in zebrafish.

Main Methods:

• Utilized zebrafish transgenically expressing GFP-LC3 to visualize autophagy activity.
• Inhibited autophagy using morpholino knockdown of key autophagy genes (atg5, atg7, becn1).
• Analyzed cardiac development in autophagy-deficient zebrafish and Atg5-deficient mice.

Main Results:

• Autophagy is active in multiple embryonic tissues, including the heart.
• Inhibition of autophagy led to developmental defects, increased cell death, abnormal heart structure, and reduced survival.
• Autophagy deficiency caused defects in cardiac looping, chamber morphology, valve development, and altered expression of key transcription factors (foxn4, tbx5, tbx2).
• Atg5-deficient mice exhibited similar cardiac defects, including abnormal Tbx2 expression and issues with valve development and chamber septation.

Conclusions:

• Autophagy plays a critical and conserved role in cardiac morphogenesis during vertebrate embryonic development.
• The findings highlight autophagy as a key regulator of heart development, essential for proper tissue and organ formation.