The 2R hypothesis: an update.
1Department of Pathology, Hokkaido University Graduate School of Medicine, North 15, West 7, Sapporo 060-8638, Japan. mkasaha@med.hokudai.ac.jp
Current Opinion in Immunology
|August 21, 2007
Summary
The two-round (2R) hypothesis suggests two whole genome duplication events shaped the vertebrate genome. Genome-wide analyses increasingly support this theory, impacting our understanding of vertebrate evolution.
Area of Science:
- Evolutionary Biology
- Genomics
- Chordate Evolution
Background:
- The two-round (2R) hypothesis, proposed by Susumu Ohno, posits genome duplication events in early vertebrate evolution.
- This hypothesis suggests two whole genome duplications occurred after urochordate emergence and before jawed vertebrate radiation.
Purpose of the Study:
- To evaluate the evidence supporting the two-round (2R) hypothesis of vertebrate genome evolution.
- To explore the implications of the 2R hypothesis for the evolution of key vertebrate systems.
Main Methods:
- Genome-wide analysis of key chordate species.
- Comparative genomics to trace gene family expansions and conserved synteny.
Main Results:
- Genome-wide analyses provide increasing support for the 2R hypothesis.
- Evidence suggests two rounds of whole genome duplication shaped the jawed vertebrate genome.
Conclusions:
- The 2R hypothesis is a robust framework for understanding vertebrate genome evolution.
- This evolutionary model has significant implications for the development of the vertebrate immune system, including MHC and NK receptors.
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