Deriving structure from evolution: metazoan segmentation

Abstract Segmentation is a common feature of disparate clades of metazoans, and its evolution is a central problem of evolutionary developmental biology. We evolved in silico regulatory networks by a mutation/selection process that just rewards the number of segment boundaries. For segmentation cont...

Full description

Saved in:
Bibliographic Details
Main Authors: Paul François, Vincent Hakim, Eric D Siggia
Format: Article
Language:English
Published: Springer Nature 2007-12-01
Series:Molecular Systems Biology
Subjects:
Online Access:https://doi.org/10.1038/msb4100192
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Abstract Segmentation is a common feature of disparate clades of metazoans, and its evolution is a central problem of evolutionary developmental biology. We evolved in silico regulatory networks by a mutation/selection process that just rewards the number of segment boundaries. For segmentation controlled by a static gradient, as in long‐germ band insects, a cascade of adjacent repressors reminiscent of gap genes evolves. For sequential segmentation controlled by a moving gradient, similar to vertebrate somitogenesis, we invariably observe a very constrained evolutionary path or funnel. The evolved state is a cell autonomous ‘clock and wavefront’ model, with the new attribute of a separate bistable system driven by an autonomous clock. Early stages in the evolution of both modes of segmentation are functionally similar, and simulations suggest a possible path for their interconversion. Our computation illustrates how complex traits can evolve by the incremental addition of new functions on top of pre‐existing traits.
ISSN:1744-4292