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ZFIN ID: ZDB-PUB-060822-1
Gene duplications and evolution of vertebrate voltage-gated sodium channels
Novak, A.E., Jost, M.C., Lu, Y., Taylor, A.D., Zakon, H.H., and Ribera, A.B.
Date: 2006
Source: Journal of molecular evolution   63(2): 208-221 (Journal)
Registered Authors: Novak, Alicia, Ribera, Angie
Keywords: Voltage-gated sodium channel, Teleosts, Gene families, Genome duplication, Gene duplication
MeSH Terms:
  • Animals
  • Base Sequence
  • Bayes Theorem
  • Blotting, Southern
  • Evolution, Molecular*
  • Exons/genetics
  • Gene Duplication*
  • Genes, Homeobox/genetics
  • Phylogeny
  • Polymerase Chain Reaction
  • Sodium Channels/genetics*
  • Vertebrates/genetics*
  • Zebrafish/genetics
  • Zebrafish Proteins/genetics
PubMed: 16830092 Full text @ J. Mol. Evol.
Voltage-gated sodium channels underlie action potential generation in excitable tissue. To establish the evolutionary mechanisms that shaped the vertebrate sodium channel alpha-subunit (SCNA) gene family and their encoded Nav1 proteins, we identified all SCNA genes in several teleost species. Molecular cloning revealed that teleosts have eight SCNA genes, compared to ten in another vertebrate lineage, mammals. Prior phylogenetic analyses have indicated that the genomes of both teleosts and tetrapods contain four monophyletic groups of SCNA genes, and that tandem duplications expanded the number of genes in two of the four mammalian groups. However, the number of genes in each group varies between teleosts and tetrapods, suggesting different evolutionary histories in the two vertebrate lineages. Our findings from phylogenetic analysis and chromosomal mapping of Danio rerio genes indicate that tandem duplications are an unlikely mechanism for generation of the extant teleost SCNA genes. Instead, analyses of other closely mapped genes in D. rerio as well as of SCNA genes from several teleost species all support the hypothesis that a whole-genome duplication was involved in expansion of the SCNA gene family in teleosts. Interestingly, despite their different evolutionary histories, mRNA analyses demonstrated a conservation of expression patterns for SCNA orthologues in teleosts and tetrapods, suggesting functional conservation.