title: The MC1R gene in the guppy (Poecilia reticulata): Genotypic and phenotypic polymorphisms.
abstract: BACKGROUND
  The guppy (Poecilia reticulata) is an important model organism for studying sexual selection; male guppies have complex and conspicuous pigmentation, and female guppies exhibit preferences for males with specific color spots. Understanding the genetic basis underlying pigmentation variation in the guppy is important for exploring the factors causing the maintenance of color polymorphism in wild populations.
  
  
  RESULTS
  We focused on the melanic black pigmentation of guppies, and examined genetic variations in the melanocortin 1 receptor (MC1R) gene because variation in this gene is known to contribute to polymorphism of melanin pigmentation in several animal species. The complete coding sequence of the guppy MC1R gene was determined, and two different MC1R alleles (963 and 969 bp) were found in wild populations. Ornamental strain guppies with a 963-bp MC1R tended to show less black pigmentation than those with a 969-bp MC1R, although the association between MC1R genotype and black pigmentation disappeared in the F2 offspring.
  
  
  CONCLUSIONS
  The guppy MC1R gene showed variation in the five wild Trinidadian populations we examined, and these populations also differed in terms of allele frequencies. We identified a significant association between black pigmentation and MC1R genotype in fish obtained from aquarium shops. However, the results from F2 families suggest that there are other genes that modify the effects of the MC1R gene.
authors.affiliation: Department of Ecology and Evolutionary Biology, Graduate School of Science, Tohoku University, Sendai 980-8578, Japan. ayumi.tezuka@gmail.com.
authors.forename: Ayumi
authors.initials: A
authors.lastname: Tezuka
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Yamamoto
authors.forename: Jun
authors.initials: J
authors.lastname: Yokoyama
authors.forename: Cock
authors.initials: C
authors.lastname: van Oosterhout
authors.forename: Masakado
authors.initials: M
authors.lastname: Kawata