Catastrophic chromosomal restructuring during genome elimination in plants

eLife

Isabelle M Henry¹  Luca Comai¹  Keith R Bradnam¹  Ian Korf²  Maruthachalam Ravi³  Martin A Lysak³  Ek Han Tan³  Mohan PA Marimuthu⁴  Simon WL Chan⁴  Terezie Mandakova⁵ 

[1] Genome Center, University of California, Davis, Davis, United States;Central European Institute of Technology, Masaryk University, Brno, Czech Republic;Department of Plant Biology, University of California, Davis, Davis, United States;Genome Center, University of California, Davis, Davis, United States;School of Biology, Indian Institute of Science Education and Research, Thiruvananthapuram, India;

关键词: genome instability;    mitosis;    chromosome segregation;   

DOI  :  10.7554/eLife.06516

来源: DOAJ

【 摘 要 】

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.

【 授权许可】

Unknown