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Published on: March 15, 2016
Evolutionary biology: hedgehog crosses the snail's midline.
Alexander J Nederbragt1, André E van Loon, Wim J A G Dictus
1Department of Developmental Biology, Utrecht University, The Netherlands. alexanderj@nederbragt.net
Nature
|June 21, 2002
Summary
The study provides evidence that the hedgehog gene, crucial for vertebrate midline patterning, is also expressed in the limpet Patella vulgata. This supports the dorsoventral axis-inversion theory, suggesting a shared evolutionary origin for nervous system development in protostomes and deuterostomes.
Area of Science:
- Developmental Biology
- Evolutionary Biology
- Neuroscience
Background:
- The dorsoventral axis-inversion theory proposes that protostomes and deuterostomes share a common ancestor with inverted body plans.
- This theory suggests homology between the ventral nervous systems of protostomes and the dorsal nervous systems of deuterostomes.
- Midline patterning genes are critical for nervous system development in both groups.
Purpose of the Study:
- To investigate the expression of a key midline patterning gene in a protostome.
- To provide experimental evidence for the dorsoventral axis-inversion theory.
- To explore the evolutionary conservation of nervous system development mechanisms.
Main Methods:
- Studied the expression pattern of an orthologue of the hedgehog gene.
- Utilized the limpet Patella vulgata larva as a model organism.
- Focused on gene expression along the dorsoventral axis.
Main Results:
- The hedgehog orthologue was found to be expressed along the ventral side (belly) of the limpet larva.
- This expression pattern mirrors the role of hedgehog in vertebrate midline patterning.
- Provides experimental support for conserved midline development mechanisms.
Conclusions:
- The findings support the hypothesis of a common ancestral mechanism for nervous system midline development.
- Suggests that the dorsoventral axis-inversion theory is supported by conserved gene expression patterns.
- Highlights the evolutionary link between protostome and deuterostome nervous system organization.
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