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The mouse ruby-eye 2(d) (ru2(d) /Hps5(ru2-d) ) allele inhibits eumelanin but not pheomelanin synthesis

Tomohisa Hirobe1, Shosuke Ito, Kazumasa Wakamatsu

  • 1Fukushima Restoration Support Headquarters, National Institute of Radiological Sciences, Chiba, Japan. thirobe@nirs.go.jp

Pigment Cell & Melanoma Research
|May 16, 2013
PubMed

Insights

The ruby-eye 2(d) mutation inhibits eumelanin production in mice by affecting melanocyte differentiation. This study found it does not impact pheomelanin synthesis in specific mouse models.

Area of Science:

  • Genetics and Molecular Biology
  • Mammalian Genetics
  • Pigmentation Research

Background:

  • The ruby-eye 2(d) mutation (Hps5(ru2-d)) causes light coats and ruby eyes by inhibiting melanocyte differentiation.
  • Key melanin synthesis genes like tyrosinase (Tyr) are affected by this mutation.
  • The effect of ru2(d) on pheomelanin synthesis in recessive yellow or agouti mice remains uncharacterized.

Purpose of the Study:

  • To investigate the impact of the ru2(d) allele on pheomelanin synthesis.
  • To determine if the ru2(d) mutation differentially affects eumelanin and pheomelanin production.

Main Methods:

  • Chemical analysis of melanin in dorsal hairs of F2 generation mice.
  • Crossbreeding of C57BL/10JHir (B10)-co-isogenic ruby-eye 2(d) mice with B10-congenic recessive yellow or agouti mice.
  • Comparison of melanin content between mutant and wild-type mice.

Main Results:

  • Eumelanin content was significantly decreased in ruby-eye 2(d) and ruby-eye 2(d) agouti mice.
  • Pheomelanin content in ruby-eye 2(d) recessive yellow and ruby-eye 2(d) agouti mice showed no significant difference compared to control groups.
  • The ru2(d) allele selectively inhibits eumelanin synthesis.

Conclusions:

  • The ru2(d) allele primarily inhibits eumelanin synthesis.
  • Pheomelanin synthesis is not significantly affected by the ru2(d) mutation.
  • This finding clarifies the specific role of Hps5(ru2-d) in mammalian pigmentation pathways.
Keywords:
EumelaninHermansky-Pudlak syndromeMelanocytePheomelaninruby-eye

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