Haploid Induction and Genome Instability.

The advent of affordable, large-scale DNA sequencing methods, coupled with advanced computing power, is empowering a detailed analysis of the structure and function of chromosomes. Genomic instability, involving chromosome number and structure changes, has been documented in multiple systems. In plants, haploid induction through genome elimination has recently been connected mechanistically to the formation of complex chromosome reorganizations, known collectively as chromoanagenesis. These abnormalities can be triggered by altering the specialized centromeric histone 3, the epigenetic determinant of centromeres, which leads to loss of centromere function and chromosome missegregation. Other historical and recent instances of genomic instability, at the same time, suggest multiple causes. Their study provides a unique opportunity for a synthesis encompassing genome evolution, its response to stress, as well as the possibility of recruiting the connected mechanisms for genome engineering-based plant breeding.