Color reversion of the albino medaka fish associated with spontaneous somatic excision of the Tol-1 transposable element from the tyrosinase gene

Makiko Tsutsumi, Shuichiro Imai, Yoriko Kyono-Hamaguchi, Satoshi Hamaguchi, Akihiko Koga, Hiroshi Hori

Research output: Contribution to journalArticle

14 Citations (Scopus)


The medaka fish albino mutant, i1 is one of the Tomita collection of medaka pigmentation mutants which exhibits a complete albino phenotype, because of inactivation of the tyrosinase gene due to insertion of a transposable element, Tol-1. Recently, mosaic black-pigmented i1 medaka fish have arisen in one of our laboratory breeding populations. Their pigmented cells have been observed in all of the tissues, including the eye and skin, in which melanin is detectable in the wild type. In this study, we analyzed the tyrosinase gene of revertants and showed Tol-1 to have been precisely excised from the gene, suggesting a causal relationship. Mosaic patterns of pigmentation indicate spontaneous somatic excision of the element from the tyrosinase gene. To our knowledge, this is the first transposable element with somatic excision activity demonstrated phenotypically in vertebrates. The pattern of pigmentation in mosaic revertants indicates frequencies of melanin pigments to be consistent with the numbers of melanophores per unit area of body sites, such as the eyes, head and dorsal trunk.

Original languageEnglish
Pages (from-to)243-247
Number of pages5
JournalPigment Cell Research
Issue number3
Publication statusPublished - 01-06-2006


All Science Journal Classification (ASJC) codes

  • Agronomy and Crop Science
  • Plant Science
  • Developmental Biology
  • Clinical Biochemistry
  • Cell Biology

Cite this