Evolutionary plasticity of developmental gene regulatory network architecture
Veronica F Hinman1, Eric H Davidson
1Department of Biological Sciences, Carnegie Mellon University, Pittsburgh, PA 15213, USA.
Summary
Sea stars and sea urchins share a conserved gene network for endoderm development. However, gene regulatory networks controlling other developmental processes have significantly diverged, revealing evolutionary flexibility in developmental gene regulation.
Area of Science:
- Developmental Biology
- Evolutionary Biology
- Genomics
Background:
- Sea stars and sea urchins diverged from a common ancestor ~500 million years ago.
- Previous studies identified a conserved five-gene network subcircuit for endoderm specification in these species.
Purpose of the Study:
- To investigate the evolutionary divergence of gene regulatory networks (GRNs) in sea stars and sea urchins.
- To compare the GRN structure surrounding a conserved endoderm specification kernel.
Main Methods:
- Comparative analysis of gene regulatory networks (GRNs).
- Examination of genomic programs for embryogenesis.
Main Results:
- A five-gene network subcircuit for endoderm specification is highly conserved.
- GRN structures upstream and downstream of this kernel have extensively diverged.
- Mesoderm specification and Delta-Notch signaling pathways show significant evolutionary differences.
Conclusions:
- Developmental gene regulatory network architecture is subject to evolutionary change.
- Subcircuit design can be preserved while gene identity evolves due to changes in cis-regulatory elements.
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