1. Catastrophic chromosomal restructuring during genome elimination in plants.
- Author
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Tan, Ek Han, Henry, Isabelle M, Ravi, Maruthachalam, Bradnam, Keith R, Mandakova, Terezie, Marimuthu, Mohan Pa, Korf, Ian, Lysak, Martin A, Comai, Luca, and Chan, Simon Wl
- Subjects
Arabidopsis ,DNA Damage ,Chromosome Aberrations ,Genomic Instability ,DNA Ligases ,DNA Primers ,Cytogenetic Analysis ,Sequence Analysis ,DNA ,Hybridization ,Genetic ,Base Sequence ,Genotype ,Polymorphism ,Single Nucleotide ,Genome ,Plant ,Molecular Sequence Data ,DNA End-Joining Repair ,DNA Ligase ATP ,arabidopsis ,chromosome segregation ,chromosomes ,genes ,genome instability ,mitosis ,Sequence Analysis ,DNA ,Hybridization ,Genetic ,Polymorphism ,Single Nucleotide ,Genome ,Plant ,Biochemistry and Cell Biology - 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.
- Published
- 2015