title: Holokinetic centromeres and efficient telomere healing enable rapid karyotype evolution.
abstract: Species with holocentric chromosomes are often characterized by a rapid karyotype evolution. In contrast to species with monocentric chromosomes where acentric fragments are lost during cell division, breakage of holocentric chromosomes creates fragments with normal centromere activity. To decipher the mechanism that allows holocentric species an accelerated karyotype evolution via chromosome breakage, we analyzed the chromosome complements of irradiated Luzula elegans plants. The resulting chromosomal fragments and rearranged chromosomes revealed holocentromere-typical CENH3 and histone H2AThr120ph signals as well as the same mitotic mobility like unfragmented chromosomes. Newly synthesized telomeres at break points become detectable 3 weeks after irradiation. The presence of active telomerase suggests a telomerase-based mechanism of chromosome healing. A successful transmission of holocentric chromosome fragments across different generations was found for most offspring of irradiated plants. Hence, a combination of holokinetic centromere activity and the fast formation of new telomeres at break points enables holocentric species a rapid karyotype evolution involving chromosome fissions and rearrangements.
authors.affiliation: Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), OT Gatersleben, Correnstrasse 3, D-06466, Stadt Seeland, Germany.
authors.forename: Maja
authors.initials: M
authors.lastname: Jankowska
authors.affiliation: Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), OT Gatersleben, Correnstrasse 3, D-06466, Stadt Seeland, Germany.
authors.forename: Jörg
authors.initials: J
authors.lastname: Fuchs
authors.affiliation: Julius Kühn-Institute, Institute for Breeding Research on Horticultural Crops, Erwin-Baur-Straße 27, D-06484, Quedlinburg, Germany.
authors.forename: Evelyn
authors.initials: E
authors.lastname: Klocke
authors.affiliation: Mendel Centre for Plant Genomics and Proteomics, CEITEC, Masaryk University, Kamenice 5, CZ-625 00, Brno, Czech Republic.|Laboratory of Functional Genomics and Proteomics, NCBR, Faculty of Science, Masaryk University, Kamenice 5, CZ-625 00, Brno, Czech Republic.
authors.forename: Miloslava
authors.initials: M
authors.lastname: Fojtová
authors.affiliation: Mendel Centre for Plant Genomics and Proteomics, CEITEC, Masaryk University, Kamenice 5, CZ-625 00, Brno, Czech Republic.|Laboratory of Functional Genomics and Proteomics, NCBR, Faculty of Science, Masaryk University, Kamenice 5, CZ-625 00, Brno, Czech Republic.
authors.forename: Pavla
authors.initials: P
authors.lastname: Polanská
authors.affiliation: Mendel Centre for Plant Genomics and Proteomics, CEITEC, Masaryk University, Kamenice 5, CZ-625 00, Brno, Czech Republic.|Laboratory of Functional Genomics and Proteomics, NCBR, Faculty of Science, Masaryk University, Kamenice 5, CZ-625 00, Brno, Czech Republic.
authors.forename: Jiří
authors.initials: J
authors.lastname: Fajkus
authors.affiliation: Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), OT Gatersleben, Correnstrasse 3, D-06466, Stadt Seeland, Germany.
authors.forename: Veit
authors.initials: V
authors.lastname: Schubert
authors.affiliation: Leibniz Institute of Plant Genetics and Crop Plant Research (IPK), OT Gatersleben, Correnstrasse 3, D-06466, Stadt Seeland, Germany. houben@ipk-gatersleben.de.
authors.forename: Andreas
authors.initials: A
authors.lastname: Houben
mesh_terms: D001324:Autoantigens; D002503:Centromere; D000076247:Centromere Protein A; D002868:Chromosomal Proteins, Non-Histone; D019457:Chromosome Breakage; D032461:Chromosomes, Plant / Q000235:genetics*; D019143:Evolution, Molecular; D006657:Histones; D059785:Karyotype; D019684:Magnoliopsida / Q000235:genetics* / Q000378:metabolism; D010940:Plant Proteins; D016615:Telomere
chemical_list: D001324:Autoantigens; D000076247:Centromere Protein A; D002868:Chromosomal Proteins, Non-Histone; D006657:Histones; D010940:Plant Proteins
keywords: Chromosome fusion and fission; De novo telomere synthesis; Holocentric chromosome; Holocentric genome evolution; Luzula elegans