Analysis of pericentromere composition and structure elucidated the history of the Hieracium alpinum L. genome, revealing waves of transposable elements insertions

The species-specific pericentromeric arrays of the H. alpinum genome are heterogeneous, exhibiting both linear and block type structures. High amounts of forward and reverse arrays of the main satDNA monomer point to multiple microinversions that could be the main mechanism for rapid structural evolution stochastically creating the uniqueness of an individual pericentromeric structure. The traces of TEs insertion waves remain in pericentromeres for a long time, thus "keeping memories" of past genomic events. We counted at least four waves of TEs insertions. In pericentromeres, TEs particles can be transformed into satDNA, which constitutes a background pool of minor families that, under certain conditions, can replace the dominant one(s).