Fat2 and Lar Define a Basally Localized Planar Signaling System Controlling Collective Cell Migration

Area of Science:

• Cell biology
• Developmental biology
• Biophysics

Background:

• Collective cell migration is crucial for tissue remodeling during development and disease.
• The molecular mechanisms coordinating individual cell movements in collective migration remain poorly understood.
• Planar cell polarity (PCP) signaling pathways regulate cell polarity and tissue organization.

Purpose of the Study:

• To elucidate the signaling mechanisms coordinating cell migration in the Drosophila follicular epithelium.
• To identify key molecules and pathways involved in regulating collective epithelial cell movement.
• To understand how cell-cell communication influences migratory behaviors.

Main Methods:

• Utilized the Drosophila follicular epithelium as a model system.
• Investigated the roles of the cadherin Fat2 and receptor tyrosine phosphatase Lar in cell migration.
• Analyzed sub-cellular protein localization and cell behaviors using advanced microscopy techniques.

Main Results:

• Identified a planar signaling system involving Fat2 and Lar that coordinates cell migration.
• Fat2 signals from trailing edges to promote leading edge protrusions in neighboring cells.
• Lar signals from leading edges to induce trailing edge retraction in adjacent cells.
• Fat2/Lar signaling mediates short-range communication, distinct from long-range PCP signaling.

Conclusions:

• Fat2 and Lar function in a novel planar cell-cell signaling pathway to coordinate epithelial cell migration.
• This signaling system regulates the dynamics of leading and trailing edges between neighboring cells.
• The findings establish a new paradigm for short-range planar cell-cell communication in promoting collective cell movement.