A positional Toll receptor code directs convergent extension in Drosophila

Area of Science:

• Developmental Biology
• Cell Biology
• Genetics

Background:

• Convergent extension is a fundamental process for body axis elongation in metazoans.
• Patterned transcription factors guide cell movements during Drosophila development.
• Mechanisms linking transcriptional patterns to cell polarity and behavior remain unclear.

Purpose of the Study:

• To elucidate how patterned transcriptional inputs control cell polarity and behavior during convergent extension.
• To identify specific molecular players mediating spatial cues in axis elongation.

Main Methods:

• Utilized Drosophila as a model organism.
• Investigated the expression patterns of Toll family receptors (Toll-2, Toll-6, Toll-8).
• Assessed the impact of disrupting Toll receptors on cell polarity, junctional remodeling, and axis elongation.

Main Results:

• Toll-2, Toll-6, and Toll-8 are expressed in overlapping transverse stripes along the anterior-posterior axis.
• These receptors function collectively to direct planar polarity and polarized cell rearrangements.
• Simultaneous disruption of all three Toll receptors significantly reduces actomyosin-driven junctional remodelling and axis elongation.
• Ectopic expression of Toll receptors can induce planar polarized actomyosin contractility.

Conclusions:

• Tissue-level Toll receptor expression patterns provide spatial signals essential for convergent extension.
• Toll receptors bridge positional information from anterior-posterior patterning to cell behaviors driving axis elongation.
• This study reveals a novel role for Toll family receptors in coordinating cell polarity and tissue morphogenesis.