Genome duplication, subfunction partitioning, and lineage divergence: Sox9 in stickleback and zebrafish.
Teleosts are the most species-rich group of vertebrates, and a genome duplication (tetraploidization) event in ray-fin fish appears to have preceded this remarkable explosion of biodiversity. What is the relationship of the ray-fin genome duplication to the teleost radiation? Genome duplication may have facilitated lineage divergence by partitioning different ancestral gene subfunctions among co-orthologs of tetrapod genes in different teleost lineages. To test this hypothesis, we investigated gene expression patterns for Sox9 gene duplicates in stickleback and zebrafish, teleosts whose lineages diverged early in Euteleost evolution. Most expression domains appear to have been partitioned between Sox9a and Sox9b before the divergence of stickleback and zebrafish lineages, but some ancestral expression domains were distributed differentially in each lineage. We conclude that some gene subfunctions, as represented by lineage-specific expression domains, may have assorted differently in separate lineages and that these may have contributed to lineage diversification during teleost evolution.
Institute of Neuroscience, University of Oregon, Eugene, Oregon 97403-1254, USA.
William A
WA
Cresko
Yi-Lin
YL
Yan
David A
DA
Baltrus
Angel
A
Amores
Amy
A
Singer
Adriana
A
Rodríguez-Marí
John H
JH
Postlethwait
D000818:Animals; D020440:Gene Duplication; D014644:Genetic Variation / Q000235:genetics; D016678:Genome; D006609:High Mobility Group Proteins / Q000235:genetics*; D006801:Humans; D010802:Phylogeny; D055758:SOX9 Transcription Factor; D012733:Sex Differentiation / Q000235:genetics; D023701:Smegmamorpha / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics*; D014714:Vertebrates / Q000145:classification; D015027:Zebrafish / Q000235:genetics*; D029961:Zebrafish Proteins / Q000235:genetics
D006609:High Mobility Group Proteins; D055758:SOX9 Transcription Factor; C527932:SOX9 protein, human; D014157:Transcription Factors; D029961:Zebrafish Proteins