Maternal factor-mediated epigenetic gene silencing in the ascidian Ciona intestinalis

Mol Genet Genomics. 2010 Jan;283(1):99-110. doi: 10.1007/s00438-009-0500-4. Epub 2009 Nov 28.


Epigenetic regulation of genes plays a critical role in achieving proper gene expression during development, and it has been reported that epigenetic modifications are associated with transposon silencing in many organisms. Here, we report a type of epigenetic gene silencing, maternal gfp/gene silencing (MGS), in the basal chordate Ciona intestinalis. A transgenic line of Ciona, Tg[MiTFr3dTPOG]45 (abbreviated as Tg45), which was created with the Minos transposon, has a tandemly arrayed insertion of gfp in the promoter region of Ci-CesA. Progeny of Tg45 showed a reduced level of GFP expression when eggs of Tg45 were fertilized with sperm of other gfp transgenic lines. Although the genotype is the same, animals developed from Tg45 sperm and the eggs of other transgenic lines did not exhibit this phenomenon, suggesting the involvement of a maternal cytoplasmic factor that influences GFP expression. The silencing starts during oogenesis and continues after fertilization without any tissue specificity. We found that post-transcriptional degradation of the gfp mRNA is involved in MGS.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Animals, Genetically Modified / genetics
  • Animals, Genetically Modified / metabolism
  • Ciona intestinalis / genetics*
  • Ciona intestinalis / physiology
  • DNA Methylation
  • Female
  • Gene Silencing*
  • Green Fluorescent Proteins / genetics
  • Male
  • Oogenesis / genetics*
  • RNA Stability


  • Green Fluorescent Proteins