Evolutionary History of C-Myc in Teleosts and Characterization of the Duplicated C-Myca Genes in Goldfish Embryos

Mol Reprod Dev. 2012 Feb;79(2):85-96. doi: 10.1002/mrd.22004. Epub 2011 Dec 28.

Abstract

c-Myc plays an important role during embryogenesis in mammals, but little is known about its function during embryonic development in teleosts. In addition, the evolutionary history of c-myc gene in teleosts remains unclear, and depending on the species, a variable number of gene duplicates exist in teleosts. To gain new insight into c-myc genes in teleosts, the present study was designed to clarify the evolutionary history of c-myc gene(s) in teleosts and to subsequently characterize DNA methylation and early embryonic expression patterns in a cyprinid fish. Our results show that a duplication of c-myc gene occurred before or around the teleost radiation, as a result of the teleost-specific whole genome duplication giving rise to c-myca and c-mycb in teleosts and was followed by a loss of the c-mycb gene in the Gasterosteiforms and Tetraodontiforms. Our data also demonstrate that both c-myc genes previously identified in carp and goldfish are co-orthologs of the zebrafish c-myca. These results indicate the presence of additional c-myca duplication in Cyprininae. We were able to identify differences between the expression patterns of the two goldfish c-myca genes in oocytes and early embryos. These differences suggest a partial sub-functionalization of c-myca genes after duplication. Despite differences in transcription patterns, both of the c-myca genes displayed similar DNA methylation patterns during early development and in gametes. Together, our results clarify the evolutionary history of the c-myc gene in teleosts and provide new insight into the involvement of c-myc in early embryonic development in cyprinids.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Embryo, Nonmammalian
  • Evolution, Molecular*
  • Fishes / embryology
  • Fishes / genetics*
  • Gene Duplication* / physiology
  • Gene Expression Regulation, Developmental
  • Genes, myc / genetics*
  • Genome
  • Goldfish / embryology
  • Goldfish / genetics*
  • Molecular Sequence Data
  • Phylogeny
  • Protein Isoforms / genetics
  • Protein Isoforms / metabolism
  • Sequence Analysis, DNA
  • Sequence Homology, Nucleic Acid
  • Synteny
  • Zebrafish / genetics
  • Zebrafish / metabolism

Substances

  • Protein Isoforms