title: Genetic Basis of Melanin Pigmentation in Butterfly Wings.
abstract: Despite the variety, prominence, and adaptive significance of butterfly wing patterns, surprisingly little is known about the genetic basis of wing color diversity. Even though there is intense interest in wing pattern evolution and development, the technical challenge of genetically manipulating butterflies has slowed efforts to functionally characterize color pattern development genes. To identify candidate wing pigmentation genes, we used RNA sequencing to characterize transcription across multiple stages of butterfly wing development, and between different color pattern elements, in the painted lady butterflyVanessa carduiThis allowed us to pinpoint genes specifically associated with red and black pigment patterns. To test the functions of a subset of genes associated with presumptive melanin pigmentation, we used clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 genome editing in four different butterfly genera.pale,Ddc, andyellowknockouts displayed reduction of melanin pigmentation, consistent with previous findings in other insects. Interestingly, however,yellow-d,ebony, andblackknockouts revealed that these genes have localized effects on tuning the color of red, brown, and ochre pattern elements. These results point to previously undescribed mechanisms for modulating the color of specific wing pattern elements in butterflies, and provide an expanded portrait of the insect melanin pathway.
authors.affiliation: Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York 14853-7202 lz355@cornell.edu robertreed@cornell.edu antonia.monteiro@nus.edu.sg.
authors.forename: Linlin
authors.identifier: 0000-0003-0247-7710
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of Biological Sciences, The George Washington University, Washington, DC 20052.
authors.forename: Arnaud
authors.identifier: 0000-0002-5980-2249
authors.initials: A
authors.lastname: Martin
authors.affiliation: Department of Biology, New York University, New York 10003-6688.
authors.forename: Michael W
authors.identifier: 0000-0002-5977-8031
authors.initials: MW
authors.lastname: Perry
authors.affiliation: Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York 14853-7202.
authors.forename: Karin R L
authors.initials: KR
authors.lastname: van der Burg
authors.affiliation: Department of Biological Sciences, National University of Singapore, 117543, Singapore.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Matsuoka
authors.affiliation: Department of Biological Sciences, National University of Singapore, 117543, Singapore lz355@cornell.edu robertreed@cornell.edu antonia.monteiro@nus.edu.sg.
authors.forename: Antónia
authors.identifier: 0000-0001-9696-459X
authors.initials: A
authors.lastname: Monteiro
authors.affiliation: Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, New York 14853-7202 lz355@cornell.edu robertreed@cornell.edu antonia.monteiro@nus.edu.sg.
authors.forename: Robert D
authors.identifier: 0000-0002-6065-6728
authors.initials: RD
authors.lastname: Reed
mesh_terms: D000818:Animals; D002080:Butterflies / Q000235:genetics* / Q000378:metabolism; D017344:Genes, Insect; D008543:Melanins / Q000235:genetics* / Q000378:metabolism; D010858:Pigmentation / Q000235:genetics*
chemical_list: D008543:Melanins
keywords: CRISPR/Cas9 genome editing; RNA-seq; butterfly wing; evo–devo; melanin; pigmentation