title: The industrial melanism mutation in British peppered moths is a transposable element.
abstract: Discovering the mutational events that fuel adaptation to environmental change remains an important challenge for evolutionary biology. The classroom example of a visible evolutionary response is industrial melanism in the peppered moth (Biston betularia): the replacement, during the Industrial Revolution, of the common pale typica form by a previously unknown black (carbonaria) form, driven by the interaction between bird predation and coal pollution. The carbonaria locus has been coarsely localized to a 200-kilobase region, but the specific identity and nature of the sequence difference controlling the carbonaria-typica polymorphism, and the gene it influences, are unknown. Here we show that the mutation event giving rise to industrial melanism in Britain was the insertion of a large, tandemly repeated, transposable element into the first intron of the gene cortex. Statistical inference based on the distribution of recombined carbonaria haplotypes indicates that this transposition event occurred around 1819, consistent with the historical record. We have begun to dissect the mode of action of the carbonaria transposable element by showing that it increases the abundance of a cortex transcript, the protein product of which plays an important role in cell-cycle regulation, during early wing disc development. Our findings fill a substantial knowledge gap in the iconic example of microevolutionary change, adding a further layer of insight into the mechanism of adaptation in response to natural selection. The discovery that the mutation itself is a transposable element will stimulate further debate about the importance of 'jumping genes' as a source of major phenotypic novelty.
authors.affiliation: Institute of Integrative Biology, University of Liverpool, Biosciences Building, Crown Street, Liverpool L69 7ZB, UK.
authors.forename: Arjen E
authors.initials: AE
authors.lastname: Van't Hof
authors.affiliation: Institute of Integrative Biology, University of Liverpool, Biosciences Building, Crown Street, Liverpool L69 7ZB, UK.
authors.forename: Pascal
authors.initials: P
authors.lastname: Campagne
authors.affiliation: Institute of Integrative Biology, University of Liverpool, Biosciences Building, Crown Street, Liverpool L69 7ZB, UK.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Rigden
authors.affiliation: Institute of Integrative Biology, University of Liverpool, Biosciences Building, Crown Street, Liverpool L69 7ZB, UK.
authors.forename: Carl J
authors.initials: CJ
authors.lastname: Yung
authors.affiliation: Institute of Integrative Biology, University of Liverpool, Biosciences Building, Crown Street, Liverpool L69 7ZB, UK.
authors.forename: Jessica
authors.initials: J
authors.lastname: Lingley
authors.affiliation: Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridgeshire CB10 1SA, UK.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Quail
authors.affiliation: Institute of Integrative Biology, University of Liverpool, Biosciences Building, Crown Street, Liverpool L69 7ZB, UK.
authors.forename: Neil
authors.initials: N
authors.lastname: Hall
authors.affiliation: Institute of Integrative Biology, University of Liverpool, Biosciences Building, Crown Street, Liverpool L69 7ZB, UK.
authors.forename: Alistair C
authors.initials: AC
authors.lastname: Darby
authors.affiliation: Institute of Integrative Biology, University of Liverpool, Biosciences Building, Crown Street, Liverpool L69 7ZB, UK.
authors.forename: Ilik J
authors.initials: IJ
authors.lastname: Saccheri
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics; D000483:Alleles; D000818:Animals; D005075:Biological Evolution; D002453:Cell Cycle / Q000235:genetics; D003116:Color; D004251:DNA Transposable Elements / Q000235:genetics*; D017344:Genes, Insect / Q000235:genetics; D006239:Haplotypes / Q000235:genetics; D007438:Introns / Q000235:genetics; D008297:Male; D008548:Melanosis / Q000235:genetics / Q000662:veterinary; D009036:Moths / Q000166:cytology / Q000235:genetics* / Q000502:physiology*; D016254:Mutagenesis, Insertional / Q000235:genetics; D009154:Mutation / Q000235:genetics*; D010641:Phenotype; D010858:Pigmentation / Q000235:genetics* / Q000502:physiology; D012641:Selection, Genetic / Q000235:genetics; D006113:United Kingdom; D014921:Wings, Animal / Q000254:growth & development / Q000502:physiology*
chemical_list: D004251:DNA Transposable Elements