title: Comparative genomics of the mimicry switch in Papilio dardanus.
abstract: The African Mocker Swallowtail, Papilio dardanus, is a textbook example in evolutionary genetics. Classical breeding experiments have shown that wing pattern variation in this polymorphic Batesian mimic is determined by the polyallelic H locus that controls a set of distinct mimetic phenotypes. Using bacterial artificial chromosome (BAC) sequencing, recombination analyses and comparative genomics, we show that H co-segregates with an interval of less than 500 kb that is collinear with two other Lepidoptera genomes and contains 24 genes, including the transcription factor genes engrailed (en) and invected (inv). H is located in a region of conserved gene order, which argues against any role for genomic translocations in the evolution of a hypothesized multi-gene mimicry locus. Natural populations of P. dardanus show significant associations of specific morphs with single nucleotide polymorphisms (SNPs), centred on en. In addition, SNP variation in the H region reveals evidence of non-neutral molecular evolution in the en gene alone. We find evidence for a duplication potentially driving physical constraints on recombination in the lamborni morph. Absence of perfect linkage disequilibrium between different genes in the other morphs suggests that H is limited to nucleotide positions in the regulatory and coding regions of en. Our results therefore support the hypothesis that a single gene underlies wing pattern variation in P. dardanus.
authors.affiliation: Department of Life Science, Natural History Museum London, London SW7 5BD, UK Department of Life Sciences, Imperial College London, South Kensington Campus, London SW7 2AZ, UK m.timmermans@imperial.ac.uk.
authors.forename: Martijn J T N
authors.initials: MJ
authors.lastname: Timmermans
authors.affiliation: Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK.
authors.forename: Simon W
authors.initials: SW
authors.lastname: Baxter
authors.affiliation: Department of Life Science, Natural History Museum London, London SW7 5BD, UK Department of Life Sciences, Imperial College London, South Kensington Campus, London SW7 2AZ, UK.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Clark
authors.affiliation: Max Planck Institute for Chemical Ecology, Beutenberg Campus, Jena 07745, Germany.
authors.forename: David G
authors.initials: DG
authors.lastname: Heckel
authors.affiliation: Max Planck Institute for Chemical Ecology, Beutenberg Campus, Jena 07745, Germany.
authors.forename: Heiko
authors.initials: H
authors.lastname: Vogel
authors.affiliation: African Butterfly Research Institute, 0800 Westlands, Nairobi 14308, Kenya.
authors.forename: Steve
authors.initials: S
authors.lastname: Collins
authors.affiliation: School of Biosciences, University of Exeter, Cornwall Campus, Daphne du Maurier Building, Penryn TR10 9EZ, UK CSIRO Ecosystem Sciences, Black Mountain Laboratories, Canberra 2601, Australia.
authors.forename: Alexie
authors.initials: A
authors.lastname: Papanicolaou
authors.affiliation: School of Biosciences, University of Exeter, Cornwall Campus, Daphne du Maurier Building, Penryn TR10 9EZ, UK.
authors.forename: Iva
authors.initials: I
authors.lastname: Fukova
authors.affiliation: Muséum National d'Histoire Naturelle, CNRS UMR 7205, CP50, 45 Rue Buffon, Paris 75005, France.
authors.forename: Mathieu
authors.initials: M
authors.lastname: Joron
authors.affiliation: Department of Life Science, Natural History Museum London, London SW7 5BD, UK Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK.
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Thompson
authors.affiliation: Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK.
authors.forename: Chris D
authors.initials: CD
authors.lastname: Jiggins
authors.affiliation: School of Biosciences, University of Exeter, Cornwall Campus, Daphne du Maurier Building, Penryn TR10 9EZ, UK.
authors.forename: Richard H
authors.initials: RH
authors.lastname: ffrench-Constant
authors.affiliation: Department of Life Science, Natural History Museum London, London SW7 5BD, UK Department of Life Sciences, Imperial College London, South Kensington Campus, London SW7 2AZ, UK.
authors.forename: Alfried P
authors.initials: AP
authors.lastname: Vogler
mesh_terms: D000818:Animals; D002080:Butterflies / Q000235:genetics* / Q000378:metabolism; D019143:Evolution, Molecular; D049750:Genome, Insect; D019476:Insect Proteins / Q000235:genetics* / Q000378:metabolism; D015810:Linkage Disequilibrium; D008969:Molecular Sequence Data; D010641:Phenotype; D017422:Sequence Analysis, DNA; D014921:Wings, Animal / Q000378:metabolism
chemical_list: D019476:Insect Proteins
keywords: Batesian mimicry; Lepidoptera; genotype–phenotype associations; polymorphism; supergene