Centrin-POC5 inner scaffold provides distal centriole integrity for sperm flagellar assembly

Area of Science:

• Cell Biology
• Reproductive Biology
• Structural Biology

Background:

• Centrioles are critical for sperm function and male fertility.
• The molecular mechanisms of centriole transformation during spermatogenesis are poorly understood.

Purpose of the Study:

• To elucidate the ultrastructural dynamics and molecular mechanisms of centriole remodeling during mouse spermatogenesis.
• To identify key molecular components essential for centriole function in male germ cells.

Main Methods:

• Application of ultrastructure expansion microscopy to visualize centrioles in mouse male germ cells.
• Analysis of centriole geometry and protein composition at different developmental stages.
• Functional characterization of the centrin-POC5 scaffold using knockout mouse models.

Main Results:

• Revealed previously unrecognized centriolar architectural changes, including geometry switching and protein removal.
• Identified the centrin-POC5 inner scaffold as crucial for distal centriole integrity and flagellar assembly.
• Demonstrated that centrin-POC5 is essential in spermatids but not in somatic cells or spermatocytes.

Conclusions:

• Provided a spatiotemporal molecular atlas of centriole remodeling during spermatogenesis.
• Uncovered the critical role of the centrin-POC5 inner scaffold in mammalian male reproduction.
• Highlighted the stage-specific importance of centriolar structures for fertility.