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A Conserved Developmental Mechanism Builds Complex Visual Systems in Insects and Vertebrates
Jean-Stéphane Joly1, Gaelle Recher2, Alessandro Brombin1
1INRA CASBAH group, Neuro-PSI Institute, CNRS, University Paris-Saclay, Gif-sur-Yvette, France.
Current Biology : CB
|October 26, 2016
Summary
The evolution of visual systems in fish and fruit flies suggests homologous neural circuits. A conserved
Area of Science:
- * Neuroscience
- * Evolutionary Biology
- * Developmental Biology
Background:
- * Vertebrate and bilaterian visual systems comprise complex neural structures.
- * While cell-type homologies are proposed, the evolution of visual neuropil architecture across phyla remains unclear.
Purpose of the Study:
- * To review evidence supporting homology in core elements of bilaterian visual circuitry.
- * To explore the conserved developmental mechanisms underlying visual system formation in fish and fruit flies.
Main Methods:
- * Comparative analysis of genetic and developmental pathways.
- * Review of existing literature on visual system development in vertebrates and invertebrates.
Main Results:
- * Profound conservation of genetic and developmental steps in eye and neuropil formation in fish and fruit flies.
- * Shared 'conveyor belt neurogenesis' mechanism involving stem cells and progenitors in partitioned neuroectodermal domains.
- * Temporal ordering and generation of diverse neurons in a topographically organized manner.
Conclusions:
- * The conserved developmental strategy supports homology between core elements of fish and fly visual circuitry.
- * 'Conveyor belt neurogenesis' is a key mechanism for generating ordered visual system architecture.
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