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The vertebrate connexin family
1The Norwegian Radium Hospital, Institute for Cancer Research, 0310, Oslo, Norway. sveinole@ulrik.uio.no
Cellular and Molecular Life Sciences : CMLS
|March 29, 2006
Summary
Connexin evolution in vertebrates reveals gene losses and duplications shaping the family from fish to mammals. The original connexin likely relates to specific fish and tunicate ortholog groups.
Area of Science:
- Evolutionary biology
- Molecular biology
- Genomics
Background:
- Connexins are chordate-specific transmembrane proteins forming gap junctions between cells.
- Vertebrate genome sequencing enables reconstruction of connexin family evolution.
- Understanding connexin evolution provides insights into cell communication.
Purpose of the Study:
- To reconstruct the evolutionary history of the connexin gene family in vertebrates.
- To identify key events like gene duplications and losses in connexin evolution.
- To infer the ancestral connexin based on extant vertebrate and tunicate sequences.
Main Methods:
- Comparative genomics analysis of connexin genes across vertebrate species (fishes to mammals).
- Phylogenetic analysis to identify gene duplications and losses.
- Comparison with newly identified connexins in tunicates to infer ancestral forms.
Main Results:
- Four connexin groups are unique to fishes.
- Connexin evolution from fish to mammals involves two gene losses and three gene duplications.
- Most connexin orthologs are conserved across vertebrates.
- The ancestral connexin may be related to Cx36, Cx39.2, Cx43.4, Cx45, or Cx47.
Conclusions:
- Connexin gene family evolution is characterized by lineage-specific events and conserved orthologs.
- Gene losses and duplications after reptile divergence significantly shaped mammalian connexin repertoires.
- Tunicate connexins offer clues to the early evolution of this crucial protein family.
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