title: The Glanville fritillary genome retains an ancient karyotype and reveals selective chromosomal fusions in Lepidoptera.
abstract: Previous studies have reported that chromosome synteny in Lepidoptera has been well conserved, yet the number of haploid chromosomes varies widely from 5 to 223. Here we report the genome (393 Mb) of the Glanville fritillary butterfly (Melitaea cinxia; Nymphalidae), a widely recognized model species in metapopulation biology and eco-evolutionary research, which has the putative ancestral karyotype of n=31. Using a phylogenetic analyses of Nymphalidae and of other Lepidoptera, combined with orthologue-level comparisons of chromosomes, we conclude that the ancestral lepidopteran karyotype has been n=31 for at least 140 My. We show that fusion chromosomes have retained the ancestral chromosome segments and very few rearrangements have occurred across the fusion sites. The same, shortest ancestral chromosomes have independently participated in fusion events in species with smaller karyotypes. The short chromosomes have higher rearrangement rate than long ones. These characteristics highlight distinctive features of the evolutionary dynamics of butterflies and moths.
authors.affiliation: 1] Department of Biosciences, University of Helsinki, FI-00014 Helsinki, Finland [2].
authors.forename: Virpi
authors.initials: V
authors.lastname: Ahola
authors.affiliation: 1] Department of Biosciences, University of Helsinki, FI-00014 Helsinki, Finland [2] Genome-Scale Biology Research Program, University of Helsinki, FI-00014 Helsinki, Finland [3] Institute of Biomedicine, University of Helsinki, FI-00014 Helsinki, Finland [4] Center of Excellence in Cancer Genetics, University of Helsinki, FI-00014 Helsinki, Finland [5] [6].
authors.forename: Rainer
authors.initials: R
authors.lastname: Lehtonen
authors.affiliation: 1] Department of Biosciences, University of Helsinki, FI-00014 Helsinki, Finland [2] Institute of Biotechnology, University of Helsinki, FI-00014 Helsinki, Finland [3].
authors.forename: Panu
authors.initials: P
authors.lastname: Somervuo
authors.affiliation: Department of Computer Science &Helsinki Institute for Information Technology HIIT, University of Helsinki, FI-00014 Helsinki, Finland.
authors.forename: Leena
authors.initials: L
authors.lastname: Salmela
authors.affiliation: 1] Department of Biosciences, University of Helsinki, FI-00014 Helsinki, Finland [2] Institute of Biotechnology, University of Helsinki, FI-00014 Helsinki, Finland.
authors.forename: Patrik
authors.initials: P
authors.lastname: Koskinen
authors.affiliation: Department of Biosciences, University of Helsinki, FI-00014 Helsinki, Finland.
authors.forename: Pasi
authors.initials: P
authors.lastname: Rastas
authors.affiliation: 1] Genome-Scale Biology Research Program, University of Helsinki, FI-00014 Helsinki, Finland [2] Institute of Biomedicine, University of Helsinki, FI-00014 Helsinki, Finland.
authors.forename: Niko
authors.initials: N
authors.lastname: Välimäki
authors.affiliation: Institute of Biotechnology, University of Helsinki, FI-00014 Helsinki, Finland.
authors.forename: Lars
authors.initials: L
authors.lastname: Paulin
authors.affiliation: Institute of Biotechnology, University of Helsinki, FI-00014 Helsinki, Finland.
authors.forename: Jouni
authors.initials: J
authors.lastname: Kvist
authors.affiliation: Department of Biology, University of Turku, FI-20014 Turku, Finland.
authors.forename: Niklas
authors.initials: N
authors.lastname: Wahlberg
authors.affiliation: 1] Institute of Biotechnology, University of Helsinki, FI-00014 Helsinki, Finland [2] Biotechnology and Food Research, MTT Agrifood Research Finland, FI-31600 Jokioinen, Finland.
authors.forename: Jaakko
authors.initials: J
authors.lastname: Tanskanen
authors.affiliation: 1] Department of Zoology, University of Cambridge, Cambridge CB2 3EJ, UK [2] Department of Biology, Pennsylvania State University, Pennsylvania 16802, USA.
authors.forename: Emily A
authors.initials: EA
authors.lastname: Hornett
authors.affiliation: Department of Zoology, University of Oxford, Oxford OX1 3PS, UK.
authors.forename: Laura C
authors.initials: LC
authors.lastname: Ferguson
authors.affiliation: College of Life Sciences, Peking University, Beijing 100871, P.R. China.
authors.forename: Shiqi
authors.initials: S
authors.lastname: Luo
authors.affiliation: College of Life Sciences, Peking University, Beijing 100871, P.R. China.
authors.forename: Zijuan
authors.initials: Z
authors.lastname: Cao
authors.affiliation: 1] Department of Biosciences, University of Helsinki, FI-00014 Helsinki, Finland [2] School of Biological Sciences, University of Bristol, Bristol BS8 1UG, UK.
authors.forename: Maaike A
authors.initials: MA
authors.lastname: de Jong
authors.affiliation: Department of Biosciences, University of Helsinki, FI-00014 Helsinki, Finland.
authors.forename: Anne
authors.initials: A
authors.lastname: Duplouy
authors.affiliation: Institute of Biotechnology, University of Helsinki, FI-00014 Helsinki, Finland.
authors.forename: Olli-Pekka
authors.initials: OP
authors.lastname: Smolander
authors.affiliation: Department of Entomology, Max Planck Institute for Chemical Ecology, D-07745 Jena, Germany.
authors.forename: Heiko
authors.initials: H
authors.lastname: Vogel
authors.affiliation: Department of Biology, Stanford University, Stanford, California 94305, USA.
authors.forename: Rajiv C
authors.initials: RC
authors.lastname: McCoy
authors.affiliation: Institute of Biotechnology, University of Helsinki, FI-00014 Helsinki, Finland.
authors.forename: Kui
authors.initials: K
authors.lastname: Qian
authors.affiliation: Department of Biosciences, University of Helsinki, FI-00014 Helsinki, Finland.
authors.forename: Wong Swee
authors.initials: WS
authors.lastname: Chong
authors.affiliation: BioMediTech, University of Tampere, FI-33520 Tampere, Finland.
authors.forename: Qin
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Department of Information Technology, University of Turku, FI-20014 Turku, Finland.
authors.forename: Freed
authors.initials: F
authors.lastname: Ahmad
authors.affiliation: BioMediTech, University of Tampere, FI-33520 Tampere, Finland.
authors.forename: Jani K
authors.initials: JK
authors.lastname: Haukka
authors.affiliation: BioMediTech, University of Tampere, FI-33520 Tampere, Finland.
authors.forename: Aruj
authors.initials: A
authors.lastname: Joshi
authors.affiliation: Department of Biosciences, University of Helsinki, FI-00014 Helsinki, Finland.
authors.forename: Jarkko
authors.initials: J
authors.lastname: Salojärvi
authors.affiliation: Department of Zoology, Stockholm University, SE-10691 Stockholm, Sweden.
authors.forename: Christopher W
authors.initials: CW
authors.lastname: Wheat
authors.affiliation: Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, D-07745 Jena, Germany.
authors.forename: Ewald
authors.initials: E
authors.lastname: Grosse-Wilde
authors.affiliation: 1] European Bioinformatics Institute, Hinxton CB10 1SD, UK [2] Baylor College of Medicine, Human Genome Sequencing Center, Houston, Texas 77030-3411, USA.
authors.forename: Daniel
authors.initials: D
authors.lastname: Hughes
authors.affiliation: 1] Genome-Scale Biology Research Program, University of Helsinki, FI-00014 Helsinki, Finland [2] Institute of Biomedicine, University of Helsinki, FI-00014 Helsinki, Finland.
authors.forename: Riku
authors.initials: R
authors.lastname: Katainen
authors.affiliation: 1] Genome-Scale Biology Research Program, University of Helsinki, FI-00014 Helsinki, Finland [2] Institute of Biomedicine, University of Helsinki, FI-00014 Helsinki, Finland.
authors.forename: Esa
authors.initials: E
authors.lastname: Pitkänen
authors.affiliation: Department of Computer Science &Helsinki Institute for Information Technology HIIT, University of Helsinki, FI-00014 Helsinki, Finland.
authors.forename: Johannes
authors.initials: J
authors.lastname: Ylinen
authors.affiliation: 1] Department of Genetic Medicine and Development, University of Geneva Medical School &Swiss Institute of Bioinformatics, 1211 Geneva, Switzerland [2] Computer Science and Artificial Intelligence Laboratory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA [3] The Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142, USA.
authors.forename: Robert M
authors.initials: RM
authors.lastname: Waterhouse
authors.affiliation: Genome-Scale Biology Research Program, University of Helsinki, FI-00014 Helsinki, Finland.
authors.forename: Mikko
authors.initials: M
authors.lastname: Turunen
authors.affiliation: 1] Genome-Scale Biology Research Program, University of Helsinki, FI-00014 Helsinki, Finland [2] Department of Pathology, University of Helsinki, FI-00014 Helsinki, Finland [3] Science for Life Laboratory, Department of Biosciences and Nutrition, Karolinska Institutet, SE-14183 Stockholm, Sweden.
authors.forename: Anna
authors.initials: A
authors.lastname: Vähärautio
authors.affiliation: Department of Biosciences, University of Helsinki, FI-00014 Helsinki, Finland.
authors.forename: Sami P
authors.initials: SP
authors.lastname: Ojanen
authors.affiliation: 1] Institute of Biotechnology, University of Helsinki, FI-00014 Helsinki, Finland [2] Biotechnology and Food Research, MTT Agrifood Research Finland, FI-31600 Jokioinen, Finland.
authors.forename: Alan H
authors.initials: AH
authors.lastname: Schulman
authors.affiliation: 1] Genome-Scale Biology Research Program, University of Helsinki, FI-00014 Helsinki, Finland [2] Science for Life Laboratory, Department of Biosciences and Nutrition, Karolinska Institutet, SE-14183 Stockholm, Sweden.
authors.forename: Minna
authors.initials: M
authors.lastname: Taipale
authors.affiliation: European Bioinformatics Institute, Hinxton CB10 1SD, UK.
authors.forename: Daniel
authors.initials: D
authors.lastname: Lawson
authors.affiliation: Department of Computer Science &Helsinki Institute for Information Technology HIIT, University of Helsinki, FI-00014 Helsinki, Finland.
authors.forename: Esko
authors.initials: E
authors.lastname: Ukkonen
authors.affiliation: Department of Computer Science &Helsinki Institute for Information Technology HIIT, University of Helsinki, FI-00014 Helsinki, Finland.
authors.forename: Veli
authors.initials: V
authors.lastname: Mäkinen
authors.affiliation: Department of Biological Sciences, University of Rhode Island, Kingston, Rhode Island 02881-0816, USA.
authors.forename: Marian R
authors.initials: MR
authors.lastname: Goldsmith
authors.affiliation: 1] Department of Biosciences, University of Helsinki, FI-00014 Helsinki, Finland [2] Institute of Biotechnology, University of Helsinki, FI-00014 Helsinki, Finland [3].
authors.forename: Liisa
authors.initials: L
authors.lastname: Holm
authors.affiliation: 1] Institute of Biotechnology, University of Helsinki, FI-00014 Helsinki, Finland [2].
authors.forename: Petri
authors.initials: P
authors.lastname: Auvinen
authors.affiliation: 1] Institute of Biotechnology, University of Helsinki, FI-00014 Helsinki, Finland [2].
authors.forename: Mikko J
authors.initials: MJ
authors.lastname: Frilander
authors.affiliation: Department of Biosciences, University of Helsinki, FI-00014 Helsinki, Finland.
authors.forename: Ilkka
authors.initials: I
authors.lastname: Hanski
mesh_terms: D000818:Animals; D001483:Base Sequence; D002080:Butterflies / Q000235:genetics*; D002869:Chromosome Aberrations; D002874:Chromosome Mapping; D019143:Evolution, Molecular; D016678:Genome / Q000235:genetics*; D059785:Karyotype; D016013:Likelihood Functions; D008957:Models, Genetic; D008969:Molecular Sequence Data; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D026801:Synteny