Evolution model of the dynamic centromeres in the genus Pennisetum. (IMAGE)
Caption
Evolution model of the dynamic centromeres in the genus Pennisetum. The centromeric sequences and structural conservation among Pennisetum species, originating from a shared ancestral foundation, underwent rapid post-speciation divergence accompanied by complete centromere turnover. Substantial differences in centromeric architecture in P. glaucum (2n = 2x = 14, x = 7) and Pennisetum alopecuroides (2n = 2x = 18, x = 9). In the tetraploid P. purpureum ‘Purple’ (2n = 4x = 28, x = 7), the fusion of centromeric repeats from its diploid progenitors has intensified subgenomic divergence of CentPs. The presence of chromosome-specific centromeric satellite clusters suggests a recombination-based homogenization mechanism operating at the chromosomal level. Notably, P. purpureum ‘Purple’ exhibits subgenome B-biased amplification of CRPs. Despite these genomic rearrangements, CENH3 nucleosome positioning remains relatively stable, and epigenetic homeostasis of centromeres is maintained in the tetraploid P. purpureum ‘Purple’.
Credit
Horticulture Research
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