title: Catastrophic chromosomal restructuring during genome elimination in plants.
abstract: Genome instability is associated with mitotic errors and cancer. This phenomenon can lead to deleterious rearrangements, but also genetic novelty, and many questions regarding its genesis, fate and evolutionary role remain unanswered. Here, we describe extreme chromosomal restructuring during genome elimination, a process resulting from hybridization of Arabidopsis plants expressing different centromere histones H3. Shattered chromosomes are formed from the genome of the haploid inducer, consistent with genomic catastrophes affecting a single, laggard chromosome compartmentalized within a micronucleus. Analysis of breakpoint junctions implicates breaks followed by repair through non-homologous end joining (NHEJ) or stalled fork repair. Furthermore, mutation of required NHEJ factor DNA Ligase 4 results in enhanced haploid recovery. Lastly, heritability and stability of a rearranged chromosome suggest a potential for enduring genomic novelty. These findings provide a tractable, natural system towards investigating the causes and mechanisms of complex genomic rearrangements similar to those associated with several human disorders.
authors.affiliation: Department of Plant Biology, University of California, Davis, Davis, United States.|Genome Center, University of California, Davis, Davis, United States.
authors.forename: Ek Han
authors.identifier: http://orcid.org/0000-0001-8872-7404
authors.initials: EH
authors.lastname: Tan
authors.affiliation: Department of Plant Biology, University of California, Davis, Davis, United States.|Genome Center, University of California, Davis, Davis, United States.
authors.forename: Isabelle M
authors.identifier: http://orcid.org/0000-0002-6796-1119
authors.initials: IM
authors.lastname: Henry
authors.affiliation: School of Biology, Indian Institute of Science Education and Research, Thiruvananthapuram, India.
authors.forename: Maruthachalam
authors.initials: M
authors.lastname: Ravi
authors.affiliation: Genome Center, University of California, Davis, Davis, United States.
authors.forename: Keith R
authors.identifier: http://orcid.org/0000-0002-3881-294X
authors.initials: KR
authors.lastname: Bradnam
authors.affiliation: Central European Institute of Technology, Masaryk University, Brno, Czech Republic.
authors.forename: Terezie
authors.initials: T
authors.lastname: Mandakova
authors.affiliation: Department of Plant Biology, University of California, Davis, Davis, United States.|Genome Center, University of California, Davis, Davis, United States.
authors.forename: Mohan Pa
authors.initials: MP
authors.lastname: Marimuthu
authors.affiliation: Genome Center, University of California, Davis, Davis, United States.|Department of Molecular and Cellular Biology, University of California, Davis, Davis, United States.
authors.forename: Ian
authors.initials: I
authors.lastname: Korf
authors.affiliation: Central European Institute of Technology, Masaryk University, Brno, Czech Republic.
authors.forename: Martin A
authors.initials: MA
authors.lastname: Lysak
authors.affiliation: Department of Plant Biology, University of California, Davis, Davis, United States.|Genome Center, University of California, Davis, Davis, United States.
authors.forename: Luca
authors.identifier: http://orcid.org/0000-0003-2642-6619
authors.initials: L
authors.lastname: Comai
authors.affiliation: Department of Plant Biology, University of California, Davis, Davis, United States.|Gordon and Betty Moore Foundation, Howard Hughes Medical Institute, University of California, Davis, Davis, United States.
authors.forename: Simon Wl
authors.initials: SW
authors.lastname: Chan
mesh_terms: D017360:Arabidopsis / Q000235:genetics*; D001483:Base Sequence; D002869:Chromosome Aberrations; D020732:Cytogenetic Analysis; D004249:DNA Damage / Q000235:genetics; D059766:DNA End-Joining Repair / Q000235:genetics; D000072481:DNA Ligase ATP; D011088:DNA Ligases / Q000235:genetics; D017931:DNA Primers / Q000235:genetics; D018745:Genome, Plant / Q000235:genetics*; D042822:Genomic Instability / Q000235:genetics / Q000502:physiology*; D005838:Genotype; D006824:Hybridization, Genetic / Q000235:genetics*; D008969:Molecular Sequence Data; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D017422:Sequence Analysis, DNA
chemical_list: D017931:DNA Primers; D011088:DNA Ligases; D000072481:DNA Ligase ATP
keywords: arabidopsis; chromosome segregation; chromosomes; genes; genome instability; mitosis