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The Drosophila eye is an outstanding model system for exploring fundamental mechanisms of growth and development. The adult eye is composed of a perfect hexagonal lattice of ∼750 unit eyes, or ommatidia, each containing precisely 20 well-characterized cells. The eye develops from the eye/antennal imaginal disc, a flattened epithelial sac. During larval and pupal development, cells in the disc grow and undergo compartmentalisation, cell cycle arrest, differentiation, directed movement, and apoptosis, all utilising gene networks and signalling pathways similar to those in vertebrates. The genetic accessibility of Drosophila, together with the precision of eye development, makes the fly retina an extremely useful system with which to investigate the roles of genes and signalling pathways in development.
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Emergence of a geometric pattern of cell fates from tissue-scale mechanics in the Drosophila eye
Pattern formation of biological structures involves the arrangement of different types of cells in an ordered spatial configuration. In this study, we investigate the mechanism of patterning the Drosophila eye epithelium into a precise triangular grid of photoreceptor clusters called ommatidia. Previous studies had led to a long-standing biochemical model whereby a reaction-diffusion process is templated by recently formed ommatidia to propagate a molecular prepattern across the eye. Here, we find that the templating mechanism is instead, mechanochemical in origin; newly born columns of differentiating ommatidia serve as a template to spatially pattern flows that move epithelial cells into position to form each new column of ommatidia. Cell flow is generated by a source and sink, corresponding to narrow zones of cell dilation and contraction respectively, that straddle the growing wavefront of ommatidia. The newly formed lattice grid of ommatidia cells are immobile, deflecting, and focusing the flow of other cells. Thus, the self-organization of a regular pattern of cell fates in an epithelium is mechanically driven.
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- PAR ID:
- 10336392
- Date Published:
- Journal Name:
- eLife
- Volume:
- 11
- ISSN:
- 2050-084X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.7554/eLife.72806
