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Published on: January 12, 2015
Nuclear hormone receptor signaling in amphioxus
Michael Schubert1, Frédéric Brunet, Mathilde Paris
1CNRS UMR5242-INRA 1288-ENS-UCBL, Institut de Génomique Fonctionnelle de Lyon, IFR128 BioSciences Lyon-Gerland, Ecole Normale Supérieure de Lyon, 46 allée d'Italie, 69364 Lyon Cedex 07, France.
Development Genes and Evolution
|September 26, 2008
Summary
The study identified 33 nuclear hormone receptors (NRs) in amphioxus, revealing the ancestral chordate NR signaling complement. This finding clarifies NR evolution and gene duplication events in vertebrates.
Area of Science:
- Evolutionary biology
- Molecular biology
- Genomics
Background:
- Nuclear hormone receptors (NRs) are crucial transcription factors for vertebrate development.
- Many NRs are ligand-activated, while others are 'orphan receptors' with unknown ligands.
- Vertebrates possess more NRs than invertebrates due to gene duplications.
Purpose of the Study:
- To investigate the evolutionary diversification of the NR superfamily in chordates.
- To determine the NR signaling complement of the ancestral chordate using amphioxus as a model.
- To understand NR gene evolution without massive duplications.
Main Methods:
- Genomic analysis of the amphioxus genome.
- Identification and characterization of NR superfamily members and coregulators.
- Comparative analysis with vertebrate NR complements.
Main Results:
- 33 NRs were identified in amphioxus, exceeding initial expectations.
- An amphioxus-specific duplication in the NR1H group accounts for increased NR numbers.
- Three heterologous NRs were found in amphioxus, unclassifiable within the NR superfamily.
- The ancestral chordate likely had 22 NRs and one copy of each NR coregulator.
Conclusions:
- The amphioxus genome provides insights into the ancestral chordate NR repertoire.
- NR gene evolution in chordates involves lineage-specific duplications.
- Understanding NR complements aids in deciphering NR-dependent signaling pathways.
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