Paradoxical methylation of the tyrosine hydroxylase gene in mouse preimplantation embryos

Tamás Arányi, Antoine Kerjean, Szabolcs Tóth, Jacques Mallet, Rolando Meloni, András Páldi

Research output: Contribution to journalArticle

6 Citations (Scopus)


The mouse tyrosine hydroxylase (Th) gene is located in an evolutionarily conserved imprinted gene cluster on distal chromosome 7. It is associated with a CpG island that spans the promoter of the gene. Using a bisulfite sequencing method we show that the Th promoter is fully methylated in both male and female mouse germ cells and in human spermatozoa, suggesting that it belongs to the newly identified category of CpG islands, the similarly methylated regions (SMRs). Contrary to other tissue-specific gene sequences, the mouse Th promoter escapes the initial wave of genome demethylation during the first few cell cycles, but becomes demethylated between the morula and the blastocyst stages. This unusual methylation ontogeny may be a characteristic of the SMRs and/or related to the localization of the Th gene in an imprinted gene cluster.

Original languageEnglish
Pages (from-to)558-563
Number of pages6
Issue number6
Publication statusPublished - Jan 1 2002



  • Bisulfite
  • CpG islands
  • DNA methylation
  • Imprinting
  • Mouse embryo
  • Preimplantation development
  • Tyrosine hydroxylase

ASJC Scopus subject areas

  • Genetics

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