Planar cell polarity: global inputs establishing cellular asymmetry

Area of Science:

• Developmental Biology
• Cell Biology
• Biophysics

Background:

• Tissues exhibit coordinated cell polarity aligned with tissue axes, a phenomenon known as planar cell polarity (PCP).
• PCP is regulated by conserved protein modules, characterized by asymmetric protein localization within the tissue plane.
• The orientation of this asymmetry is influenced by global directional cues within the tissue.

Purpose of the Study:

• To review current models and recent findings on the establishment of global planar cell polarity patterns.
• To highlight the roles of tissue-level gradients, local organizer signals, and mechanical forces in guiding PCP.
• To provide an overview of the mechanisms controlling directional cell polarization in developing tissues.

Main Methods:

• This work is a review, synthesizing existing research and theoretical models.
• It integrates findings from experimental studies across various model organisms.
• The focus is on conceptual frameworks and mechanistic insights rather than novel experimental data.

Main Results:

• Global PCP patterns are established through a combination of intrinsic and extrinsic factors.
• Tissue-level gradients provide long-range directional information for cell polarization.
• Local organizer signals and mechanical forces contribute to refining and maintaining PCP orientation.

Conclusions:

• The precise orientation of planar cell polarity is a complex process influenced by multiple integrated signaling pathways and physical cues.
• Understanding these mechanisms is crucial for comprehending tissue development and organization.
• Future research should further elucidate the interplay between biochemical signals and mechanical forces in PCP establishment.