Chiral forces organize left-right patterning in C. elegans by uncoupling midline and anteroposterior axis

Area of Science:

• Developmental Biology
• Cell Biology
• Genetics

Background:

• Left-right (LR) patterning is a fundamental process in bilaterian embryogenesis, yet its underlying mechanisms remain largely unknown.
• Establishing LR asymmetry is critical for proper organogenesis and body plan formation.

Purpose of the Study:

• To elucidate the mechanism of LR patterning in C. elegans embryogenesis.
• To understand how the embryo establishes a distinct midline and initiates differential cell fate induction.

Main Methods:

• Observation of early C. elegans embryos using live imaging.
• Analysis of cell behaviors, including asymmetric protrusions and collective cell movements.
• Investigating the role of noncanonical Wnt signaling and cortical contractility.

Main Results:

• The eight-cell C. elegans embryo establishes a midline tilted rightward from the anteroposterior (AP) axis.
• Cells exhibit LR asymmetric protrusions and a handed collective movement, termed chiral morphogenesis.
• Differential regulation of cortical contractility and noncanonical Wnt signaling are key to chiral morphogenesis, timed by a neighboring cytokinetic furrow.

Conclusions:

• Chiral morphogenesis provides a novel mechanism for establishing LR asymmetry in C. elegans.
• This process involves a unique interplay between cell contractility, signaling pathways, and a developmental timing mechanism.