Catastrophic chromosomal restructuring during genome elimination in plants.
Ek Han TanIsabelle M HenryMaruthachalam RaviKeith R BradnamTerezie MandakovaMohan Pa MarimuthuIan KorfMartin A LysakLuca ComaiSimon Wl ChanPublished in: eLife (2015)
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.
Keyphrases
- copy number
- genome wide
- dna methylation
- single molecule
- dna repair
- dna damage
- transcription factor
- papillary thyroid
- squamous cell carcinoma
- gene expression
- circulating tumor
- cell cycle
- emergency department
- cell free
- oxidative stress
- human health
- adverse drug
- pluripotent stem cells
- induced pluripotent stem cells
- plant growth
- circulating tumor cells