<p>In organisms ranging from vertebrates to plants, major components of centromeres are rapidly evolving repeat sequences, such as tandem repeats (TRs) and transposable elements (TEs), which harbour centromere-specific histone H3 (CENH3)<sup><CitationRef CitationID="CR1">1</CitationRef>,<CitationRef CitationID="CR2">2</CitationRef></sup>. Complete centromere structures recently determined in human and <i>Arabidopsis</i> suggest frequent integration and purging of retrotransposons within the TR regions of centromeres<sup><CitationRef AdditionalCitationIDS="CR4" CitationID="CR3">3</CitationRef>–<CitationRef CitationID="CR5">5</CitationRef></sup>. Despite the high impact of ‘centrophilic’ retrotransposons on the paradox of rapid centromere evolution, the mechanisms involved in centromere targeting remain poorly understood in any organism. Here we show that both <i>Ty3</i> and <i>Ty1</i> long terminal repeat retrotransposons rapidly turnover within the centromeric TRs of <i>Arabidopsis</i> species. We demonstrate that the <i>Ty1/Copia</i> element <i>Tal1</i> (<i>Transposon of Arabidopsis lyrata 1</i>) integrates de novo into regions occupied by CENH3 in <i>Arabidopsis</i> <i>thaliana</i>, and that ectopic expansion of the CENH3 region results in spread of <i>Tal1</i> integration regions. The integration spectra of chimeric TEs reveal the key structural variations responsible for contrasting chromatin-targeting specificities to centromeres versus gene-rich regions, which have recurrently converted during the evolution of these TEs. Our findings show the impact of centromeric chromatin on TE-mediated rapid centromere evolution, with relevance across eukaryotic genomes.</p>

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Centrophilic retrotransposon integration via CENH3 chromatin in Arabidopsis

  • Sayuri Tsukahara,
  • Alexandros Bousios,
  • Estela Perez-Roman,
  • Sota Yamaguchi,
  • Basile Leduque,
  • Aimi Nakano,
  • Matthew Naish,
  • Akihisa Osakabe,
  • Atsushi Toyoda,
  • Hidetaka Ito,
  • Alejandro Edera,
  • Sayaka Tominaga,
  • Juliarni,
  • Kae Kato,
  • Shoko Oda,
  • Soichi Inagaki,
  • Zdravko Lorković,
  • Kiyotaka Nagaki,
  • Frédéric Berger,
  • Akira Kawabe,
  • Leandro Quadrana,
  • Ian Henderson,
  • Tetsuji Kakutani

摘要

In organisms ranging from vertebrates to plants, major components of centromeres are rapidly evolving repeat sequences, such as tandem repeats (TRs) and transposable elements (TEs), which harbour centromere-specific histone H3 (CENH3)1,2. Complete centromere structures recently determined in human and Arabidopsis suggest frequent integration and purging of retrotransposons within the TR regions of centromeres35. Despite the high impact of ‘centrophilic’ retrotransposons on the paradox of rapid centromere evolution, the mechanisms involved in centromere targeting remain poorly understood in any organism. Here we show that both Ty3 and Ty1 long terminal repeat retrotransposons rapidly turnover within the centromeric TRs of Arabidopsis species. We demonstrate that the Ty1/Copia element Tal1 (Transposon of Arabidopsis lyrata 1) integrates de novo into regions occupied by CENH3 in Arabidopsis thaliana, and that ectopic expansion of the CENH3 region results in spread of Tal1 integration regions. The integration spectra of chimeric TEs reveal the key structural variations responsible for contrasting chromatin-targeting specificities to centromeres versus gene-rich regions, which have recurrently converted during the evolution of these TEs. Our findings show the impact of centromeric chromatin on TE-mediated rapid centromere evolution, with relevance across eukaryotic genomes.