Number of genes controlling a quantitative trait in a hybrid zone of the aposematic frog Ranitomeya imitator

Jacob Schack Vestergaard, Evan Twomey, Rasmus Larsen, Kyle Summers, Rasmus Nielsen

Research output: Contribution to journalJournal articleResearchpeer-review


The number of genes controlling mimetic traits has been a topic of much research and discussion. In this paper, we examine a mimetic, dendrobatid frog Ranitomeya imitator, which harbours extensive phenotypic variation with multiple mimetic morphs, not unlike the celebrated Heliconius system. However, the genetic basis for this polymorphism is unknown, and not easy to determine using standard experimental approaches, for this hard-to-breed species. To circumvent this problem, we first develop a new protocol for automatic quantification of complex colour pattern phenotypes from images. Using this method, which has the potential to be applied in many other systems, we define a phenotype associated with differences in colour pattern between different mimetic morphs. We then proceed to develop a maximum-likelihood method for estimating the number of genes affecting a quantitative trait segregating in a hybrid zone. This method takes advantage of estimates of admixture proportions obtained using genetic data, such as microsatellite markers, and is applicable to any other system where a phenotype has been quantified in an admixture/introgression zone. We evaluate the method using extensive simulations and apply it to the R. imitator system. We show that probably one or two, or at most three genes, control the mimetic phenotype segregating in a R. imitator hybrid zone identified using image analyses.
Original languageEnglish
JournalProceedings of the Royal Society B: Biological Sciences
Issue number1807
Pages (from-to)1-10
Publication statusPublished - 2015


  • Evolution
  • Genomics
  • Ranitomeya imitator
  • Hybridization
  • Image analysis
  • Quantitative phenotyping


Dive into the research topics of 'Number of genes controlling a quantitative trait in a hybrid zone of the aposematic frog Ranitomeya imitator'. Together they form a unique fingerprint.

Cite this